UFC 3-320-01A Welding - Whole Building Design Guide

UFC 3-320-01A Welding - Whole Building Design Guide
UFC 3-320-01A
1 March 2005
ED
UNIFIED FACILITIES CRITERIA (UFC)
C
AN
C
EL
L
WELDING – DESIGN PROCEDURES
AND INSPECTIONS
APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED
UFC 3-320-01A
1 March 2005
UNIFIED FACILITIES CRITERIA (UFC)
WELDING – DESIGN PROCEDURES AND INSPECTIONS
ED
Any copyrighted material included in this UFC is identified at its point of use.
Use of the copyrighted material apart from this UFC must have the permission of the
copyright holder.
U.S. ARMY CORPS OF ENGINEERS (Preparing Activity)
NAVAL FACILITIES ENGINEERING COMMAND
EL
L
AIR FORCE CIVIL ENGINEER SUPPORT AGENCY
Record of Changes (changes are indicated by \1\ ... /1/)
Date
Location
C
AN
C
Change No.
This UFC supersedes TI 809-26, dated 1 March 2000. The format of this UFC does not conform to
UFC 1-300-01; however, the format will be adjusted to conform at the next revision. The body of
this UFC is the previous TI 809-26, dated 1 March 2000.
1
UFC 3-320-01A
1 March 2005
FOREWORD
\1\
The Unified Facilities Criteria (UFC) system is prescribed by MIL-STD 3007 and provides
planning, design, construction, sustainment, restoration, and modernization criteria, and applies
to the Military Departments, the Defense Agencies, and the DoD Field Activities in accordance
with USD(AT&L) Memorandum dated 29 May 2002. UFC will be used for all DoD projects and
work for other customers where appropriate. All construction outside of the United States is
also governed by Status of forces Agreements (SOFA), Host Nation Funded Construction
Agreements (HNFA), and in some instances, Bilateral Infrastructure Agreements (BIA.)
Therefore, the acquisition team must ensure compliance with the more stringent of the UFC, the
SOFA, the HNFA, and the BIA, as applicable.
EL
L
ED
UFC are living documents and will be periodically reviewed, updated, and made available to
users as part of the Services’ responsibility for providing technical criteria for military
construction. Headquarters, U.S. Army Corps of Engineers (HQUSACE), Naval Facilities
Engineering Command (NAVFAC), and Air Force Civil Engineer Support Agency (AFCESA) are
responsible for administration of the UFC system. Defense agencies should contact the
preparing service for document interpretation and improvements. Technical content of UFC is
the responsibility of the cognizant DoD working group. Recommended changes with supporting
rationale should be sent to the respective service proponent office by the following electronic
form: Criteria Change Request (CCR). The form is also accessible from the Internet sites listed
below.
UFC are effective upon issuance and are distributed only in electronic media from the following
source:
•
Whole Building Design Guide web site http://dod.wbdg.org/.
AN
AUTHORIZED BY:
C
Hard copies of UFC printed from electronic media should be checked against the current
electronic version prior to use to ensure that they are current.
C
______________________________________
DONALD L. BASHAM, P.E.
Chief, Engineering and Construction
U.S. Army Corps of Engineers
______________________________________
KATHLEEN I. FERGUSON, P.E.
The Deputy Civil Engineer
DCS/Installations & Logistics
Department of the Air Force
2
______________________________________
DR. JAMES W WRIGHT, P.E.
Chief Engineer
Naval Facilities Engineering Command
______________________________________
Dr. GET W. MOY, P.E.
Director, Installations Requirements and
Management
Office of the Deputy Under Secretary of Defense
(Installations and Environment)
ED
TI 809-26
1 March 2000
EL
L
Technical Instructions
C
AN
C
Welding Design Procedures
And Inspections
Headquarters
US Army Corps of Engineers
Engineering and Construction Division
Directorate of Military Programs
Washington, DC 20314-1000
CEMP-E
TI 809-26
1 March 2000
ED
TECHNICAL INSTRUCTIONS
EL
L
WELDING - DESIGN PROCEDURES AND INSPECTIONS
Any copyrighted material included in this document is identified at its point of use.
Use of the copyrighted material apart from this document must have the permission of the copyright
holder.
AN
C
Approved for public release; distribution is unlimited.
C
Record of Changes (changes indicated \1\.../1/)
No. Date
Location
This Technical Instruction supersedes TM 5-805-7, Welding Design, Procedures
and Inspection dated 20 May 1985
CEMP-E
TI 809-26
1 March 2000
FOREWORD
ED
These technical instructions (TI) provide design and construction criteria and apply to all U.S. Army
Corps of Engineers (USACE) commands having military construction responsibilities. TI will be used for
all Army projects and for projects executed for other military services or work for other customers where
appropriate.
EL
L
TI are living documents and will be periodically reviewed, updated, and made available to users as part
of the HQUSACE responsibility for technical criteria and policy for new military construction. CEMP-ET
is responsible for administration of the TI system; technical content of TI is the responsibility of the
HQUSACE element of the discipline involved. Recommended changes to TI, with rationale for the
changes, should be sent to HQUSACE, ATTN: CEMP-ET, 20 Massachusetts Ave., NW, Washington, DC
20314-1000.
C
TI are effective upon issuance. TI are distributed only in electronic media through the TECHINFO
Internet site http://www.hnd.usace.army.mil/technifo/index.htm and the Construction Criteria Base (CCB)
system maintained by the National Institute of Building Sciences at Internet site
http://www.ccb.org/html/home/. Hard copies of these instructions produced by the user from the
electronic media should be checked against the current electronic version prior to use to assure that the
latest instructions are used.
C
AN
FOR THE COMMANDER:
DWIGHT A. BERANEK, P.E.
Chief, Engineering and Construction Division
Directorate of Military Programs
CEMP-E
TI 809-26
1 March 2000
WELDING - DESIGN PROCEDURES AND INSPECTIONS
Table of Contents
Page
CHAPTER 1. GENERAL
PURPOSE AND SCOPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
APPLICABILITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
BIBLIOGRAPHY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CHAPTER 2. APPLICABLE DESIGN SPECIFICATIONS
ED
Paragraph 1.
2.
3.
2.
1-1
1-1
1-1
1-1
C
AN
C
EL
L
Paragraph 1. GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
a. Specification Cycles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
b. Specification Conflicts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
c. New Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
d. Preferred Design Methodology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
e. Standards Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
2. USACE AND OTHER MILITARY DOCUMENTS . . . . . . . . . . . . . . . . . . . . . 2-1
a. TI 809-01 Load Assumptions for Buildings . . . . . . . . . . . . . . . . . . . . . . . 2-1
b. TI 809-02 Structural Design Criteria for Buildings . . . . . . . . . . . . . . . . . 2-1
c. TI 809-04 Seismic Design for Buildings . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
d. TI 809-05 Seismic Evaluation and Rehabilitation for Buildings . . . . . . . . 2-2
e. TI 809-07 Design of Cold-Formed Load Bearing Steel Systems and
Masonry Veneer / Steel Stud Walls . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
f. TI 809-30 Metal Building Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
g. TM 5-809-6 Structural Design Criteria for Structures Other than Buildings 2-2
3. AISC SPECIFICATIONS AND STANDARDS . . . . . . . . . . . . . . . . . . . . . . . . 2-2
a. Metric Load and Resistance Design Specification for Structural Steel
Buildings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
b. Load and Resistance Factor Design Specification for Structural Steel
Buildings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
c. Specification for Structural Steel Buildings - Allowable Stress Design and
Plastic Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
d. Seismic Provisions for Structural Steel Buildings . . . . . . . . . . . . . . . . . . 2-3
e. Code of Standard Practice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
f. Manual of Steel Construction, LRFD, Metric Conversion . . . . . . . . . . . . 2-3
g. Manual of Steel Construction, LRFD . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
h. Manual of Steel Construction, ASD . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
4. AWS SPECIFICATIONS AND STANDARDS . . . . . . . . . . . . . . . . . . . . . . . . 2-4
a. D1.1 Structural Welding Code - Steel . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
b. D1.3 Structural Welding Code - Sheet Steel . . . . . . . . . . . . . . . . . . . . . 2-4
c. D1.4 Structural Welding Code - Reinforcing Steel . . . . . . . . . . . . . . . . . 2-4
d. A2.4 Standard Symbols for Welding, Brazing and Nondestructive Testing 2-4
e. A5-series Filler Metal Related Specifications . . . . . . . . . . . . . . . . . . . . . 2-4
5. FEDERAL EMERGENCY MANAGEMENT AGENCY . . . . . . . . . . . . . . . . . . 2-5
i
CEMP-E
TI 809-26
1 March 2000
CHAPTER 3. WELDING PROCESSES AND MATERIALS
ED
a. FEMA 267 & 267B Steel Moment Frame Structures - Interim
Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
b. FEMA 267 Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
c. FEMA 273 NEHRP Guidelines for the Seismic Rehabilitation of Buildings .2-5
d. FEMA 302 NEHRP Recommended Provisions for Seismic Regulations for
new Buildings and Other Structures . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
AN
C
EL
L
Paragraph 1. WELDING AND RELATED PROCESSES . . . . . . . . . . . . . . . . . . . . . . . . . .
a. General - Welding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
b. General - Heating and Thermal Cutting . . . . . . . . . . . . . . . . . . . . . . . . .
c. General - Weld Heat-Affected Zone . . . . . . . . . . . . . . . . . . . . . . . . . . .
d. Project Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2. APPLICATION OF HEAT FOR WELDING . . . . . . . . . . . . . . . . . . . . . . . . .
a. Cooling Rate Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
b. Preheat for Prequalified Applications . . . . . . . . . . . . . . . . . . . . . . . . . . .
c. Preheat for Non-prequalified Applications . . . . . . . . . . . . . . . . . . . . . . .
d. Preheat for Sheet Steel to Structural Steel . . . . . . . . . . . . . . . . . . . . . .
e. Interpass Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
f. Postheat (PWHT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3. APPLICATION OF HEAT FOR STRAIGHTENING AND CAMBERING . . . .
a. Principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
b. Cambering Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
c. Maximum Temperatures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4. THERMAL CUTTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
a. Oxyfuel Cutting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
b. Plasma Arc Cutting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
c. Edge Quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5. AIR CARBON ARC GOUGING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
a. Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
b. Surface Finishing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-1
3-1
3-1
3-1
3-1
3-1
3-1
3-2
3-4
3-4
3-4
3-5
3-5
3-5
3-5
3-5
3-5
3-5
3-5
3-6
3-6
3-6
3-6
CHAPTER 4. STRUCTURAL STEELS
C
Paragraph 1. AISC AND AWS LISTED STRUCTURAL STEELS . . . . . . . . . . . . . . . . . . .
a. AISC Approved Steels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
b. AWS Prequalified Steels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
c. AWS Approved Steels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
d. Matching Filler Metals for Prequalified Steels . . . . . . . . . . . . . . . . . . . .
e. Matching Filler Metals for Non-qualified Steels . . . . . . . . . . . . . . . . . . .
f. Unlisted Steels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2. WELDABILITY OF STRUCTURAL STEELS . . . . . . . . . . . . . . . . . . . . . . . . .
a. Chemical Composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
b. Carbon Equivalency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3. PROPERTY ENHANCEMENTS FOR STRUCTURAL STEELS . . . . . . . . . .
a. Yield to Ultimate Strength Ratio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ii
4-1
4-1
4-1
4-2
4-2
4-3
4-4
4-4
4-4
4-6
4-8
4-8
CEMP-E
TI 809-26
1 March 2000
ED
b. Killed Steel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9
c. Fine Grain Practice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9
d. Toughness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9
e. Improved Through-thickness Properties . . . . . . . . . . . . . . . . . . . . . . . . 4-10
f. Normalizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10
4. SELECTION OF STRUCTURAL STEELS FOR ENVIRONMENTAL
EXPOSURE AND SERVICE APPLICATIONS . . . . . . . . . . . . . . . . . . . . . . 4-10
a. High-seismic Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10
b. Fatigue Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10
c. Cold Weather Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12
d. High Stress / Strain / Restraint Applications . . . . . . . . . . . . . . . . . . . . . 4-13
5. AVAILABILITY OF STRUCTURAL STEELS . . . . . . . . . . . . . . . . . . . . . . . 4-13
CHAPTER 5. DESIGN FOR WELDING
C
AN
C
EL
L
Paragraph 1. GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
a. Engineer’s Responsibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
2. GOOD DESIGN PRACTICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
a. Availability of Materials, Equipment and Personnel . . . . . . . . . . . . . . . . 5-1
b. Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
c. Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2
d. Joint Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2
e. Prequalified Joint Details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
f. Qualified Joint Details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
g. Distortion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
3. DESIGN AND FABRICATION OF WELDED JOINTS . . . . . . . . . . . . . . . . . 5-4
a. Effective Weld Size / Throat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
b. Allowable Stresses / Design Strengths . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
c. Minimum / Maximum Weld Sizes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6
d. Maximum Fillet Weld Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6
e. Available Design Aids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6
f. Weld Access Holes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6
g. Reentrant Corners . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6
h. Heavy Section Joint Provisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6
i. Backing Bars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7
j. Weld Tabs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7
k. Welding Sequence and Distortion Control . . . . . . . . . . . . . . . . . . . . . . . 5-8
l. Lamellar Tearing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8
m. Brittle Fracture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9
4. DESIGN FOR CYCLICALLY LOADED STRUCTURES (FATIGUE) . . . . . . . 5-9
a. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9
b. Fatigue Design Details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10
c. Allowable Stress Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11
d. Fatigue Life Enhancement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11
5. HIGH SEISMIC APPLICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11
a. Latest Guidance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12
b. Applicability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12
c. Materials Concerns and Specifications . . . . . . . . . . . . . . . . . . . . . . . . 5-12
d. Joint Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-13
iii
CEMP-E
TI 809-26
1 March 2000
e. Joint Detail Modifications and Enhancements . . . . . . . . . . . . . . . . . . . 5-13
f. Inspection Enhancements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-13
CHAPTER 6. STUD WELDING
GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
STUD WELDING PROCESS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
STUD BASE QUALIFICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
WELDING PERSONNEL QUALIFICATION . . . . . . . . . . . . . . . . . . . . . . . . .
PRE-PRODUCTION TESTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CHAPTER 7. WELDING TO EXISTING STRUCTURES
ED
Paragraph 1.
2.
3.
4.
5.
6.
AN
C
EL
L
Paragraph 1. GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2. DETERMINING WELDABILITY OF EXISTING STRUCTURAL STEELS . .
a. Investigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
b. Carbon Equivalency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3. WELDING TO OLDER STRUCTURAL STEELS . . . . . . . . . . . . . . . . . . . . .
4. INTERMIXING WELD PROCESSES AND FILLER METALS . . . . . . . . . . . .
a. FCAW-S Deposits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
b. Investigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
c. Other Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5. STRENGTH REDUCTION EFFECTS AND OTHER CONCERNS WHEN
WELDING UNDER LOAD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
a. Elevated Temperature Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
b. Welding Direction and Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6. HAZARDOUS MATERIALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6-1
6-1
6-1
6-1
6-1
6-2
7-1
7-1
7-1
7-1
7-1
7-1
7-1
7-2
7-2
7-2
7-2
7-2
7-2
CHAPTER 8. QUALITY ASSURANCE AND INSPECTION
C
Paragraph 1. GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2. REVIEWING AND APPROVING WELDING PROCEDURES . . . . . . . . . . . .
a. WPS Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
c. AWS Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
d. AISC Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
e. WPS Prequalification Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
f. WPS Qualification Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
g. Guidance for Engineering Review of Procedures Submitted by
Contractors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3. WELDING PERSONNEL QUALIFICATION . . . . . . . . . . . . . . . . . . . . . . . . .
a. Personnel Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
b. Qualification Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
c. Contractor Responsibilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
d. Qualification Testing by Others . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4. INSPECTOR QUALIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
a. General Welding and Visual Inspection . . . . . . . . . . . . . . . . . . . . . . . . .
iv
8-1
8-1
8-1
8-1
8-1
8-2
8-2
8-2
8-2
8-2
8-3
8-3
8-3
8-3
8-3
CEMP-E
TI 809-26
1 March 2000
b. NDT Personnel Qualification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4
EL
L
ED
5. INSPECTION CATEGORIES AND TASKS . . . . . . . . . . . . . . . . . . . . . . . . . 8-5
a. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5
b. Pre-project Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5
c. Prior to Welding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-6
d. During Welding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-8
e. After Welding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-8
f. Nondestructive Testing Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-9
6. WELD QUALITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-12
a. Engineer’s Responsibility for Acceptance Criteria . . . . . . . . . . . . . . . . 8-12
b. D1.1 Acceptance Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-12
c. NDT Acceptance Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-12
d. Alternate Acceptance Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-12
7. REPAIRS TO BASE METAL AND WELDS . . . . . . . . . . . . . . . . . . . . . . . . 8-13
a. Mill Defects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-13
b. Laminations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-13
c. Weld Discontinuities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-13
d. Root Opening Corrections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-13
e. Mislocated Holes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-13
CHAPTER 9. OTHER WELDING SPECIFICATIONS AND STANDARDS
C
TUBULAR STRUCTURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SHEET STEEL WELDING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
REINFORCING STEEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
STAINLESS STEEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ALUMINUM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
BRIDGES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MATERIAL HANDLING EQUIPMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CAST STEEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CAST IRON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
WROUGHT IRON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
OTHER GOVERNING SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . .
a. ASME . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
b. API . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
c. AWWA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C
AN
Paragraph 1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
9-1
9-1
9-1
9-1
9-1
9-1
9-1
9-1
9-2
9-2
9-2
9-2
9-2
9-2
CHAPTER 10. SAFETY & ENVIRONMENTAL CONSIDERATIONS
Paragraph 1. GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2. SAFETY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
a. Fire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
b. Confined Spaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
c. Eye Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
d. Burn Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
e. Electrocution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
f. Fumes and Gases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
v
10-1
10-1
10-1
10-1
10-1
10-1
10-2
10-2
CEMP-E
TI 809-26
1 March 2000
g. Further Guidance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-2
3. ENERGY CONSUMPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-3
APPENDIX A. REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1
ED
APPENDIX B. BIBLIOGRAPHY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1
APPENDIX C. WELDING PROCESSES
3.
4.
AN
5.
EL
L
2.
SHIELDED METAL ARC WELDING (SMAW) . . . . . . . . . . . . . . . . . . . . . . . C-1
a. Process Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-1
b. Filler Metal Designation, Specification and Certification . . . . . . . . . . . . . C-1
c. Advantages, Disadvantages and Limitations . . . . . . . . . . . . . . . . . . . . . C-3
FLUX CORED ARC WELDING (FCAW) . . . . . . . . . . . . . . . . . . . . . . . . . . . C-8
a. Process Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-8
b. Filler Metal Designation, Specification and Certification . . . . . . . . . . . . . C-8
c. Advantages, Disadvantages and Limitations . . . . . . . . . . . . . . . . . . . . . C-9
GAS METAL ARC WELDING (GMAW . . . . . . . . . . . . . . . . . . . . . . . . . . . C-15
a. Process Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-15
b. Filler Metal Designation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-15
c. Advantages, Disadvantages and Limitations . . . . . . . . . . . . . . . . . . . . C-16
SUBMERGED ARC WELDING (SAW) . . . . . . . . . . . . . . . . . . . . . . . . . . . C-21
a. Process Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-21
b. Filler Metal Designation, Specification and Certification . . . . . . . . . . . . C-22
c. Advantages, Disadvantages and Limitations . . . . . . . . . . . . . . . . . . . . C-23
GAS TUNGSTEN ARC WELDING (GTAW) . . . . . . . . . . . . . . . . . . . . . . . C-29
a. Process Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-29
b. Filler Metal Designation, Specification and Certification . . . . . . . . . . . . C-29
c. Advantages, Disadvantages and Limitations . . . . . . . . . . . . . . . . . . . . C-29
ELECTROSLAG WELDING (ESW) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-31
a. Process Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-31
b. Filler Metal Designation, Specification and Certification . . . . . . . . . . . . C-31
c. Advantages, Disadvantages and Limitations . . . . . . . . . . . . . . . . . . . . C-31
ELECTROGAS WELDING (EGW) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-33
a. Process Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-33
b. Filler Metal Designation, Specification and Certification . . . . . . . . . . . . C-33
c. Advantages, Disadvantages and Limitations . . . . . . . . . . . . . . . . . . . . C-33
C
Paragraph 1.
6
C
7.
APPENDIX D. NONDESTRUCTIVE TESTING METHODS
Paragraph 1. VISUAL TESTING (VT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
a. Method Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
b. Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2. PENETRANT TESTING (PT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
a. Method Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
vi
D-1
D-1
D-1
D-3
D-3
CEMP-E
TI 809-26
1 March 2000
C
AN
C
EL
L
ED
b. Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-3
3. MAGNETIC PARTICLE TESTING (MT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-5
a. Method Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-5
b. Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-5
4. ULTRASONIC TESTING (UT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-7
a. Method Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-7
b. Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-7
5. RADIOGRAPHIC TESTING (RT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-10
a. Method Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-10
b. Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-10
6. OTHER METHODS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-12
vii
CEMP-E
TI 809-26
1 March 2000
CHAPTER 1
GENERAL
ED
1. PURPOSE AND SCOPE. This document provides criteria and guidance for the design and
specification of welded structural components and systems in accordance with current technology,
standards and materials. This includes information on design approaches, use of technical manuals,
guidance on the application of codes and industry standards, and the design and specification of welded
details, inspection and quality. The scope of this document is welding for general building construction
for military applications, and does not include underwater, piping, or cryogenic applications, bridges,
sheet steels, or the welding of materials other than structural steel. A building is defined as any structure,
fully or partially enclosed, used or intended for sheltering persons or property.
2. APPLICABILITY. These instructions are applicable to all USACE elements having military
construction responsibilities.
EL
L
3. REFERENCES. Appendix A contains a list of references pertaining to this document.
C
AN
C
4. BIBLIOGRAPHY. A bibliography of publications that provides additional information and background
data is in Appendix B.
1-1
CEMP-E
TI 809-26
1 March 2000
CHAPTER 2
APPLICABLE DESIGN SPECIFICATIONS
1. GENERAL.
ED
a. Specification Cycles. Building design and welding design are governed by a variety of
specifications and standards, as listed. Because of the varying focus of each standard or specification,
and the varying dates of adoption and publication, the standards and specifications are in a constant
cycle of revision.
b. Specification Conflicts. Conflicts may arise between codes as new research and methods are
adopted in one code before another. There are also specific exceptions one code may take with another,
as the AISC Specification does with AWS D1.1, listing those exceptions in AISC Specification section
J1.2.
EL
L
c. New Materials. New steels and welding materials, adopted by the industry, may not be listed in the
codes for periods of several years because of the adoption and printing cycles. Within AWS standards,
the filler metal specifications are being revised for metrication. The AWS D1.1 code is also being fully
metricated for the year 2000, with independent dimensional units and values. Those values established
as of the date of this document have been adopted. Others may change with the publication of the D1.12000 Structural Welding Code - Steel.
AN
C
d. Preferred Design Methodology. The American Institute of Steel Construction provides two
methodologies for the design of steel-framed buildings. The first method is Allowable Stress Design
(ASD), which provides adequate strength based upon service load conditions. All loads are assumed to
have the same variability. The second method, Load and Resistance Factor Design (LRFD), is a more
modern probabilistic approach also known as limit states design. LRFD uses load factors and load
combinations applied to service loads, and resistance (strength reduction) factors applied to the nominal
resistance of the component to achieve a design strength. Both methods are in current practice. The use
of the LRFD method is preferred over the use of the ASD method, but is not required.
e. Standards Evaluation. Users of this document should evaluate the various standards listed, and
new standards that may be published, for suitable application. It may be necessary to take exceptions to
various code provisions, or to expand the code provisions through the use of the project specifications, to
resolve conflicting issues and to permit new materials.
C
2. USACE AND OTHER MILITARY DOCUMENTS.
a. TI 809-01 Load Assumptions for Buildings. This document provides minimum snow and wind
loads plus frost penetration data to be used in the design and construction of buildings and other
structures. Except as designated within the document, all loadings are based upon ASCE 7-95, Minimum
Design Loads for Buildings and Other Structures. Buildings are categorized according to occupancy.
b. TI 809-02 Structural Design Criteria for Buildings. General structural design guidance for buildings,
and for building systems constructed of concrete, masonry, steel and wood is presented in this TI
document. The design requirements provided herein, or cited by reference, are based on national
building codes, industry standards, and technical manuals developed by the Army, Navy, and Air Force.
2-1
CEMP-E
TI 809-26
1 March 2000
Instructions necessary to provide serviceable buildings and to assure load path integrity and continuity is
included. Requirements unique to Army, Navy, and Air Force facilities are indicated. Supplemental
information to help engineers interpret and apply code provisions, and meet serviceability and strength
performance objectives is also included in the TI.
ED
c. TI 809-04 Seismic Design for Buildings. This document provides qualified designers with the
criteria and guidance for the performance-based seismic analysis and design of new military buildings,
and the non-structural systems and components in those buildings. Chapter 7 includes discussion of
structural steel framing systems, but does not provide specific details for welded connections in those
systems.
EL
L
d. TI 809-05 Seismic Evaluation and Rehabilitation for Buildings. This document is intended to
provide qualified designers with the necessary criteria and guidance for the performance-based seismic
analysis and design of new military buildings, and the nonstructural systems and components in the
buildings. The primary basis for this document is the 1997 edition of the NEHRP Provisions for Seismic
Regulations for New Buildings and Other Structures (FEMA 302). This document provides guidance in
the interpretation and implementation of the FEMA 302 provisions for the Life Safety performance
objective for all buildings, and it provides criteria for the design and analysis of buildings with enhanced
performance objectives.
e. TI 809-07 Design of Cold-Formed Load Bearing Steel Systems and Masonry Veneer / Steel Stud
Walls. This document provides design guidance on the use of cold-formed steel systems for both loadbearing and nonload-bearing applications. Cold-formed steel members are generally of a thickness that
welding is governed by AWS D1.3 Structural Welding Code - Sheet Steel, rather than AWS D1.1
Structural Welding Code - Steel, and therefore are not covered by TI 809-26.
AN
C
f. TI 809-30 Metal Building Systems. This document provides guidance on the use of Metal Building
Systems, defined as a complete integrated set of mutually dependent components and assemblies that
form a building, including primary and secondary framing, covering and accessories. These types of
structures were previously referred to as pre-engineered buildings. Paragraph 5.i addresses welding for
manufacturers not AISC certified in Category MB.
g. TM 5-809-6 Structural Design Criteria for Structures Other Than Buildings. This document will
become TI 809-03. Revise as needed.
3. AISC SPECIFICATIONS AND STANDARDS.
C
a. Metric Load and Resistance Design Specification for Structural Steel Buildings. The Metric LRFD
Specification contains provisions regarding welding design and application. Section J contains design
provisions, and Section M contains limited supplemental information regarding quality and inspection.
The Metric LRFD Specification, published in 1994, is based upon AWS D1.1-92, and takes exception to
certain provisions of that edition. This metric specification is a dimensional conversion of the December
1, 1993 customary units edition. The principles and concepts of these two specifications (metric and
customary) are identical, only the units differ. It is anticipated that a new LRFD Specification, containing
both SI and US Customary Units within one document, will be published by AISC in early 2000.
b. Load and Resistance Factor Design Specification for Structural Steel Buildings. The LRFD
Specification contains provisions regarding welding design and application. Section J contains design
provisions, and Section M contains limited supplemental information regarding quality and inspection.
2-2
CEMP-E
TI 809-26
1 March 2000
The LRFD Specification, published in 1993, is based upon AWS D1.1-92, and takes exception to certain
provisions of that edition. It is anticipated that a new LRFD Specification, containing both SI and US
Customary Units within one document, will be published by AISC in early 2000.
ED
c. Specification for Structural Steel Buildings - Allowable Stress Design and Plastic Design. The ASD
Specification contains provisions regarding welding design and application. Section J contains design
provisions, and Section M contains limited supplemental information regarding quality and inspection.
The ASD Specification, published in 1989, is based upon the use of AWS D1.1-88, and takes exception
to certain provisions of AWS D1.1. Publication of an updated or new ASD Specification is not being
planned by AISC.
EL
L
d. Seismic Provisions for Structural Steel Buildings. This AISC document addresses the design and
construction of structural steel and composite steel / reinforced concrete building systems in seismic
regions. It is applicable for use in either LRFD or ASD. The provisions are for the members and
connections that comprise the Seismic Force Resisting System (SFRS) in buildings that are classified as
Seismic Design Category D or higher in FEMA 302, NEHRP Recommended Provisions for Seismic
Regulations for New Buildings and Other Structures. These structures include all buildings with an S DS >=
0.50g (SD1 >= 0.20g), and Seismic Use Group III when S DS >= 0.33g (SD1 >= 0.133g). See TI 809-04,
Chapter 4. The Seismic Provisions document cites AWS D1.1-96 as the reference welding standard. Part
I, Section 7.3 is applicable to welded joints, containing provisions regarding Welding Procedure
Specification approvals, filler metal toughness requirements, and special concerns for discontinuities in
SFRS members.
C
e. Code of Standard Practice. The AISC Code of Standard Practice defines practices adopted as
commonly accepted standards of the structural steel fabricating industry. In the absence of other contract
documents, the trade practices of the document govern the fabrication and erection of structural steel.
Within the document, Materials are discussed in Section 5, Fabrication in Section 6, Erection in Section
7, and Quality Control in Section 8.
AN
f. Manual of Steel Construction, LRFD, Metric Conversion. The AISC Manual of Steel Construction
contains informational tables and design aids, as well as the AISC Specifications themselves. The
Manual contains welding design aids in Volume II - Connections. Chapter 8 includes prequalified joint
details, AWS welding symbols, tables for eccentrically loaded fillet welds, design examples, and general
information regarding welding. Design examples are contained within Chapter 9 for Simple Shear and
PR Moment Connections, Chapter 10 for Fully Restrained (FR) Moment Connections, and Chapter 11 for
Connections for Tension and Compression. One is cautioned that the welded prequalified joint tables are
based upon AWS D1.1-92, and have been substantially revised in subsequent editions of AWS D1.1.
C
g. Manual of Steel Construction, LRFD. The AISC Manual of Steel Construction contains
informational tables and design aids, as well as the AISC Specifications themselves. When using LRFD,
the Manual of Steel Construction, 2nd Edition, is applicable, and is in two volumes. The Manual contains
welding design aids in Volume II - Connections. Chapter 8 includes prequalified joint details, AWS
welding symbols, tables for eccentrically loaded fillet welds, design examples, and general information
regarding welding. Design examples are contained within Chapter 9 for Simple Shear and PR Moment
Connections, Chapter 10 for Fully Restrained (FR) Moment Connections, and Chapter 11 for
Connections for Tension and Compression. One is cautioned that the welded prequalified joint tables are
based upon AWS D1.1-92, and have been substantially revised in subsequent editions of AWS D1.1.
h. Manual of Steel Construction, ASD. The AISC Manual of Steel Construction contains informational
2-3
CEMP-E
TI 809-26
1 March 2000
ED
tables and design aids, as well as the AISC Specifications themselves. The 9 th Edition of the Manual
contains welding design aids in Part 4 - Connections, including prequalified joint details, AWS welding
symbols, tables for eccentrically loaded fillet welds, and design examples. One is cautioned that the
welded prequalified joint tables are based upon AWS D1.1-88, and have been substantially revised in
subsequent editions of AWS D1.1. The 9th Edition ASD Manual is supplemented by a separate book,
Volume II - Connections. Chapter 2 contains general information regarding welding, Chapter 3 contains
design examples for Simple Shear Connections, Chapter 4 contains Moment Connections, and Chapter
6 contains Column Connections.
4. AWS SPECIFICATIONS AND STANDARDS.
EL
L
a. D1.1 Structural Welding Code - Steel. ANSI/AWS D1.1 contains the requirements for fabricating
and erecting welded steel structures. The D1.1 Code is limited to carbon and low-alloy steels, of
minimum specified yield strength not greater than 690 MPa (100 ksi), 3.2 mm (1/8 in.) in thickness or
greater. It is not applicable to pressure vessel or pressure piping applications. D1.1 contains eight
sections: (1) General Requirements, (2) Design of Welded Connections, (3) Prequalification, (4)
Qualification, (5) Fabrication, (6) Inspection, (7) Stud Welding, and (8) Strengthening and Repair. It also
contains both mandatory and nonmandatory annexes, plus commentary. It is updated biannually, in even
years.
C
b. D1.3 Structural Welding Code - Sheet Steel. ANSI/AWS D1.3 covers arc welding of sheet and strip
steels, including cold-formed members that are equal to or less than 4.8 mm (3/16 in.) in nominal
thickness. Arc spot, arc seam, and arc plug welds are included in the Code. The D1.3 Code is applicable
when welding sheet steels to other sheet steels, or when welding to other thicker structural members.
With the latter application, the use of AWS D1.1 is also required for the structural steel. The D1.3 Code
contents are similar to AWS D1.1, except Sections 7 and 8 are not included.
AN
c. D1.4 Structural Welding Code - Reinforcing Steel. ANSI/AWS D1.4 covers the welding of
reinforcing steel, as used in concrete construction. Welding of reinforcing steel to reinforcing steel, and
reinforcing steel to other carbon and low-alloy steels, is covered. With the latter application, the use of
AWS D1.1 is also required for the structural steel. D1.4 follows a different organizational structure than
AWS D1.1 and D1.3, and includes the following sections: (1) General Provisions, (2) Allowable Stresses,
(3) Structural Details, (4) Workmanship, (5) Technique, (6) Qualification, and (7) Inspection, plus
annexes.
C
d. A2.4 Standard Symbols for Welding, Brazing and Nondestructive Testing. ANSI/AWS A2.4
contains standards for the application of welding symbols on structural design and detail drawings, as
well as examples of their use. Part A of the document covers Welding Symbols, Part B covers Brazing
Symbols, and Part C covers Nondestructive Examination Symbols. The symbols and use specified in
this document supersedes symbols that may be shown in other AWS and industry documents, as they
may be incorrect or outdated in the other documents.
e. A5-series Filler Metal Related Specifications. ANSI/AWS A5-series documents establish the
requirements for electrodes, fluxes, and shielding gases, as applicable, for given general types of
electrodes and given welding processes. The requirements include, as applicable, chemical composition
of the electrode, moisture content, usability, markings, packaging, storage, certifications, and the astested mechanical properties (strength, ductility, and toughness) and soundness of weld metal. An
Appendix or Annex is provided to explain the provisions and provide additional information. The A52-4
CEMP-E
TI 809-26
1 March 2000
series specifications applicable to structural steel are listed in Appendix A - References, of TI 809-26.
5. FEDERAL EMERGENCY MANAGEMENT AGENCY.
ED
a. FEMA 267 and 267B Steel Moment Frame Structures - Interim Guidelines. The Interim Guidelines,
published in 1995, are applicable to steel moment-resisting frame structures incorporating fully restrained
connections in which the girder flanges are welded to the columns, and are subject to significant inelastic
demands from strong earthquake ground motion. Guideline recommendations are provided based upon
research conducted under the SAC Joint Venture, Phase 1 project. The Guidelines include information
regarding the pre-earthquake evaluation and inspection of existing buildings, post-earthquake evaluation
and inspection of existing buildings, repairing damaged buildings, retrofitting existing damaged and
undamaged buildings, and designing, constructing and inspecting new buildings.
FEMA 267A was published as an additional advisory to FEMA 267, based upon information available as
of August 1996. A second advisory, FEMA 267B, was published in mid-1999, replacing FEMA 267A.
EL
L
b. FEMA 267 Replacement. A series of five new documents are planned for publication in early 2000,
based upon the results of the SAC Joint Venture Phase 2 project. These will supersede FEMA 267 and
issued advisories. The documents will be as follows: (1) Seismic Design Criteria for New MomentResisting Steel Frame Construction, (2) Post-Earthquake Evaluation and Repair Criteria for Welded
Moment-Resisting Steel Frame Construction, (3) Seismic Evaluation and Upgrade Criteria for Existing
Steel Moment-Resisting Frame Construction, and (4) Quality Assurance Guidelines for Moment-Resisting
Steel Frame Construction, and (5) Recommended Specifications for Moment-Resisting Steel Frame
Buildings.
C
c. FEMA 273 NEHRP Guidelines for the Seismic Rehabilitation of Buildings. FEMA 273 provides
guidelines for the seismic rehabilitation of buildings constructed of steel or cast iron, concrete, masonry,
wood and light metal, including foundations and architectural, mechanical and electrical components.
The document is oriented toward structural analysis procedures, with limited information regarding
specific details for welding or inspection.
C
AN
d. FEMA 302 NEHRP Recommended Provisions for Seismic Regulations for New Buildings and
Other Structures. FEMA 302 provides minimum design criteria for the design and construction of
structures to resist earthquake motions. Included are provisions for foundations, steel structures,
concrete structures, composite structures, masonry structures, seismic isolation, related building
components, and nonbuilding structures such as racks, towers, piers and wharves, tanks and vessels,
stacks and chimneys, electrical distribution structures, and several other structures. Not included in the
provisions are certain classes of one-and two-family residential structures, agricultural structures, and
structures in areas of low seismicity.
2-5
CEMP-E
TI 809-26
1 March 2000
CHAPTER 3
WELDING PROCESSES AND MATERIALS
1. WELDING AND RELATED PROCESSES.
ED
a. General - Welding. The proper selection of welding processes, materials, and procedures is vital to
achieving the strength and quality necessary for adequate performance in the structure. The contract
documents, prepared by the Engineer, should specify any special requirements for materials, inspection,
or testing beyond that required by the codes and standards.
b. General - Heating and Thermal Cutting. The application of heat, whether for straightening, cutting,
or welding, may have a significant effect upon the mechanical properties of the steel, weld, and heataffected zones. Should any limitations in the use of heat be needed beyond those specified in the codes,
the contract documents prepared by the Engineer should so state.
EL
L
c. General - Weld Heat-Affected Zone. The heat-affected zone (HAZ) is the portion of steel
immediately adjacent to the weld that has been metallurgically modified by the heat of the welding. The
microstructure has been changed, and the mechanical properties typically have been degraded with
reduced ductility and toughness, but with increased strength. Also, hydrogen from the welding operation
will have migrated into the hot HAZ, then subsequently been trapped within the metallurgical structure,
embrittling the steel. The hydrogen will eventually migrate out the HAZ, at rates dependent upon initial
hydrogen levels, thickness and temperature. The HAZ is typically about 3 mm (1/8 in.) thick for common
size welds, primarily depending upon welding heat input.
AN
C
d. Project Specifications. In most cases, it is adequate to simply require compliance with the codes.
The contractor may be allowed the full choice of welding processes and materials. The use of “matching”
prequalified filler metals is encouraged. When SMAW is performed, the use of low-hydrogen electrodes
is encouraged. Recently, the use of specified toughness levels for filler metals in specific seismic
building applications has been added to standard practice. For further guidance in the use and selection
of welding processes and materials, see Appendix C.
2. APPLICATION OF HEAT FOR WELDING.
C
a. Cooling Rate Control. Preheat is used primarily to slow the cooling rate of the heat-affected zone
(HAZ). Because preheating slows the cooling rate, the steel remains at an elevated temperature longer,
increasing the rate and time of hydrogen diffusion and reducing the risk of hydrogen-assisted cracking.
Preheat also aids in the removal of surface moisture and organic compounds, if present, from the
surface to be welded, reducing porosity and other discontinuities. Preheating may also reduce residual
stresses and improve the toughness of the completed joint.
(1) High Cooling Rates. A high cooling rate may cause a hard, martensitic HAZ microstructure with
a higher risk of cracking during cooling. The HAZ will also contain higher levels of hydrogen, also
embrittling the steel and increasing the risk of cracking.
(2) Low Cooling Rates. Conversely, a very low cooling rate can detrimentally affect toughness
because of grain growth. When preheat above approximately 300 oC (550oF) is used, weld metal
properties may be degraded as well. If the steel is manufactured using heat treatment processes, such as
3-1
CEMP-E
TI 809-26
1 March 2000
quenched and tempered steels, too high a preheat may affect steel properties by retempering the steel.
For quenched and tempered steels, preheat and interpass temperatures above 230 oC (450oF) should be
avoided.
ED
b. Preheat for Prequalified Applications. The basic values for minimum preheat temperatures for
prequalified structural steels are provided in AWS D1.1 Table 3.2. A summary of this table is provided as
Table 3-1, with suggestions in Table 3-2 for non-prequalified steels. With any non-prequalified steel, a
competent welding advisor should be consulted. When steels of different categories are joined, use the
higher preheat required for their respective thicknesses.
(1) Category A is applicable when non-low hydrogen SMAW electrodes are used. This is permitted
as prequalified only for AWS Group I steels, but is not recommended practice. See Appendix C,
Paragraph 1b. Because of the higher diffusible hydrogen present when non-low hydrogen electrodes are
used, higher preheats are required to allow additional time for hydrogen to escape from the heat-affected
zone. When low-hydrogen SMAW electrodes are used, the preheat can be reduced because of the
reduced hydrogen levels present.
EL
L
(2) Category D is applicable to A913 steel, a thermo-mechanically controlled processed (TMCP)
steel that has low carbon and alloy levels. Weldability tests have been conducted to document that the
steel may be welded without preheat, provided the steel temperature is above 0 oC (32oF), and an
electrode classified as H8 (tested under ANSI/AWS A4.3 for 8 mL or less of diffusible hydrogen per 100
g of deposited weld metal) or lower is used.
AN
C
(3) Users are cautioned that the use of these minimum preheat tables may not be sufficient to
avoid cracking in all cases. Increased preheat temperatures may be necessary in situations involving
higher restraint, higher hydrogen levels, lower welding heat input, or with steel compositions at the upper
end of their respective specification. Conversely, preheats lower than those tabulated may be adequate
for conditions of low restraint, low hydrogen levels, higher welding heat input, and steel compositions low
in carbon and other alloys. Additional guidance for these situations may be found in AWS D1.1 Annex XI,
Guideline on Alternative Methods for Determining Preheat. The Guide considers hydrogen level, steel
composition, and restraint and allows for calculation of the estimated preheat necessary to avoid cold
cracking. When higher preheats are calculated, it is advisable to use these values, provided maximum
preheat levels are not exceeded. When lower preheat values are calculated, the AWS D1.1 Code
requires the WPS to be qualified using the lower preheat value. Such testing may not always adequately
replicate restraint conditions, so caution is advised.
C
(4) Although not required for building applications under AWS D1.1, consideration for higher
preheat and interpass temperature requirements may be made for critical applications where fracture
would result in a catastrophic collapse. For these conditions, AWS D1.5 Bridge Welding Code Tables
12.3, 12.4 and 12.5 provide recommended values. Seismic applications with routine building structures is
not considered appropriate for requiring higher levels of preheat and interpass temperatures, and AWS
D1.1 Table 3.2 should suffice.
3-2
CEMP-E
TI 809-26
1 March 2000
Table 3-1. Minimum Preheat and Interpass Temperatures for AISC-Approved
Structural Steels Prequalified under AWS D1.1
B
Round and Rectangular
Sections
A53, grade B (round)
A500, grades A and B
(round)
A500, grades A and B
(rectangular)
A501 (round)
C
0oC (32oF)1
over 19 to 38.1 mm (incl.)
(3/4 to 1-1/2 in.)
66oC (150oF)
over 38.1 to 63.5 mm
(incl.)
(1-1/2 to 2-1/2 in.)
107oC
(225oF)
over 63.5 mm
(2-1/2 in.)
Shapes and Plates
A36
A529, grade 42
A709, grades 36, 50 & 50W
A572, grades 42 and
50
A588, 100 mm (4 in.) thick
and
under
A913, grade 50
A992, grade 50 (shapes
only)
Round and Rectangular
Sections
A53, grade B (round)
A500, grades A and B
(round)
A500, grades A and B
(rectangular)
A501 (round)
A618, grades lb, II, & III
(round)
AN
When using
SMAW with
low-hydrogen
electrodes, or
FCAW, GMAW or
SAW
3 to 19 mm (incl.)
(1/8 to 3/4 in.)
Minimum
Preheat and
Interpass
Temperature
ED
When using
SMAW with
other than lowhydrogen
electrodes
Shapes and Plates
A36
A529, grade 42
A709, grade 36
EL
L
A
Structural Steel
C
Category
Material Thickness of
Thickest Part at Point of
Welding
3-3
150oC
(300oF)
3 to 19 mm (incl.)
(1/8 to 3/4 in.)
0oC (32oF)1
over 19 to 38.1 mm (incl.)
(3/4 to 1-1/2 in.)
10oC (50oF)
over 38.1 to 63.5 mm
(incl.)
(1-1/2 to 2-1/2 in.)
over 63.5 mm
(2-1/2 in.)
66oC (150oF)
107oC
(225oF)
CEMP-E
Category
TI 809-26
1 March 2000
Material Thickness of
Thickest Part at Point of
Welding
Structural Steel
C
Shapes and Plates
A913, Grades 50, 60, and
65
C
When using
SMAW with lowhydrogen
electrodes, or
FCAW, GMAW or
SAW, with
electrodes of
class H8 or
lower
10oC (50oF)
over 19 to 38.1 mm (incl.)
(3/4 to 1-1/2 in.)
66oC (150oF)
over 38.1 to 63.5 mm
(incl.)
(1-1/2 to 2-1/2 in.)
107oC
(225oF)
over 63.5 mm
(2-1/2 in.)
150oC
(300oF)
ED
D
Shapes and Plates
A572, grades 60 and 65
A709, grade 70W2
A852, grades 702
A913, grades 60 and 65
3 to 19 mm (incl.)
(1/8 to 3/4 in.)
EL
L
When using
SMAW with lowhydrogen
electrodes, or
FCAW, GMAW or
SAW
Minimum
Preheat and
Interpass
Temperature
all thicknesses
0oC (32oF)1
- If the steel is below 0oC (32oF), the steel, in the vicinity of welding, must be raised to and
maintained at a minimum temperature of 21oC (70oF) prior to and during welding.
2
- Maximum preheat and interpass temperature of 200oC (400oF) for thicknesses up to 40 mm
(1-1/2 inches) inclusive, and 230oC (450oF) for thickness greater than 40 mm (1-1/2 inches).
C
AN
1
3-4
CEMP-E
TI 809-26
1 March 2000
Table 3-2. Suggested Minimum Preheat and Interpass Temperatures for AISCApproved Structural Steels Not Prequalified under AWS D1.1.
(Seek advice of competent welding consultant prior to use of this Table.)
Catego
ry
Structural Steel
Minimum Preheat and Interpass
Temperature
ED
Shapes and Plates
A529, grade 46
A283 (plates)
NPQ-A
same as Table 3-1, Category A
Round and Rectangular
Sections
EL
L
A500, grade C (round)
Shapes and Plates
A242, all grades
A529, grades 50 and 55
NPQ-B
C
A588, over 4" thick
Round and Rectangular
Sections
same as Table 3-1, Category B
AN
A500, grade C (rectangular)
A618, grades Ib, II, and III
(round)
C
A847
c. Preheat for Non-prequalified Applications. Preheat requirements for non-prequalified steels and
applications may be determined using rational engineering judgement considering material composition,
restraint, hydrogen levels, and experience. Table 3-2 provides suggested values for common structural
steels not currently listed in AWS D1.1. Other steels should be evaluated by a competent welding
consultant. The use of AWS D1.1 Annex XI is suggested, with suitable qualification testing to be
performed to verify the analytical results.
d. Preheat for Sheet Steel to Structural Steel. When the structural steel element is of a grade or
thickness requiring preheat under the provisions of AWS D1.1, preheat must be provided to the structural
steel element. The sheet steel itself need not be preheated.
3-5
CEMP-E
TI 809-26
1 March 2000
e. Interpass Temperature. Interpass temperature is the temperature maintained during welding, until
completion of the weld joint. Minimum and maximum interpass temperatures are typically the same as
the minimum and maximum preheat temperatures, but may vary in specific WPSs.
(1) Thicker materials may absorb enough heat from the weld region that it is necessary to reapply
heat to the weld region prior to resuming welding of the joint.
ED
(2) With maximum interpass temperature considerations, it may be necessary to pause welding
operations to allow the steel to cool to below the maximum interpass temperature before resuming
welding. Accelerated cooling using water should not be permitted, but the use of forced air is acceptable.
Cooling time may be necessary for larger multi-pass welds on thinner materials or smaller members.
EL
L
(3) When necessary to shut down welding operations on a joint prior to joint completion, it should
be verified that adequate welding has been completed to sustain any currently applied or anticipated
loadings until completion of the joint. The joint may be allowed to cool below the prescribed interpass
temperature, but must be reheated to the required preheat / interpass temperature before resumption of
welding of the joint.
C
f. Postheat (PWHT). Postheating is the continued application of heat following completion of the weld
joint. It is not required by specification, but may be used in some cases when conditions of high restraint,
poor weldability steels, and poor hydrogen control exist. In most cases, when proper attention is applied
to preheat and interpass temperatures, and adequate control of hydrogen levels is maintained,
postheating is not necessary to avoid cold cracking. Under the difficult conditions mentioned, it may be
adequate to slow cooling rates through the use of insulating blankets applied immediately after
completion of welding. The PWHT described in AWS D1.1 Section 5.8, is for the purpose of stress relief,
not cracking control.
3. APPLICATION OF HEAT FOR STRAIGHTENING AND CAMBERING.
AN
a. Principle. Heat applied from a heating torch may be used to straighten curved or distorted
members, and also to camber or curve members when desired. The method is commonly called “flame
shrinking”, because the heat is applied to the part of the member that needs to become shorter.
b. Cambering Procedure. Cambering a beam with positive camber requires heat to be applied to the
bottom flange of the beam. It is recommended to first apply a V-heat to the web, starting with a point
near the top, to soften the web and minimize web crippling that may occur if only the flange is heated.
C
c. Maximum Temperatures. The temperature to which the steel may be heated as a part of the
straightening or cambering process is limited to 650 oC (1200oF) for most structural steels, and to 590 oC
(1100oF) for quenched and tempered steels. See AWS D1.1 Section 5.26.2. For TMCP steels, the
manufacturer’s recommendations for maximum temperatures should be followed. It is recommended that
accelerated cooling using water mist not be used until the temperature of the steel has dropped below
approximately 300oC (600oF).
4. THERMAL CUTTING. Thermal cutting is used in steel fabrication to cut material to size and to
perform edge preparation for groove welding. Thermal cutting is generally grouped into two categories oxyfuel gas cutting, also commonly called flame cutting or burning, and plasma arc cutting.
3-6
CEMP-E
TI 809-26
1 March 2000
a. Oxyfuel Cutting. With oxyfuel gas cutting (OFC), the steel is heated with a torch to its ignition
temperature, then exposed to a stream of oxygen from the same torch. The oxygen causes rapid
oxidation, or “burning” to occur, which itself creates additional heat to allow the process to continue. The
force of the oxygen stream blows away the molten steel, leaving a cut edge. The fuel gas used in oxyfuel
cutting may be natural gas, propane, acetylene, propylene, MPS, or other proprietary fuel gases.
ED
b. Plasma Arc Cutting. Plasma arc cutting (PAC) is sometimes used in shop fabrication, and is
generally limited to steels 25 mm (1 in.) thick or less. Similar to oxyfuel cutting, the steel is heated to the
point of melting, only this function is performed using an electric arc. The molten steel is then removed
by the high velocity stream of plasma (ionized gas) created by the arc itself, within the cutting torch.
Gases used for PAC include nitrogen, argon, air, oxygen, and mixtures of nitrogen/oxygen and
argon/hydrogen. With plasma arc cutting, the area of steel heated by the process is less, resulting in less
steel metallurgically affected by the heat of cutting, as well as less distortion. PAC generates
considerable fume and noise, and therefore a water table and water shroud is typically used to minimize
these undesirable environmental effects.
EL
L
c. Edge Quality. The quality of thermally cut edges is governed by AWS D1.1 Section 5.15.4. Limits
are placed on surface roughness, as measured using ANSI/ASME B46.1, Surface Texture (Surface
Roughness, Waviness and Lay). A plastic sample, AWS C4.1-G, Oxygen Cutting Surface Roughness
Gauge, is typically used for visual comparison in lieu of physical measurement of surface roughness.
Limitations are also placed on the depth and sharpness of gouges and notches. AISC, in Section M2.2,
takes a minor exception to AWS D1.1 quality criteria.
C
5. AIR CARBON ARC GOUGING. Air carbon arc gouging (ACAG) is commonly used to perform edge
preparation for groove joints (especially J- and U-grooves), to remove unacceptable discontinuities from
weld deposits, and to remove temporary attachments such as backing bars or lifting lugs. It may also be
used to remove entire welds when structural repairs or modifications are necessary.
AN
a. Process. The process appears similar to SMAW, with an electrode holder and a single electrode,
and is usually performed manually, however, the electrode is a carbon electrode covered with a copper
sheath. The electrode creates a controlled arc, melting the steel, which is quickly followed by the focused
application of compressed air from the electrode holder. The air provides continued rapid oxidation, as
well as removes the molten steel from the area. For complete information, see ANSI/AWS C5.3,
Recommended Practices for Air Carbon Arc Gouging and Cutting.
C
b. Surface Finishing. Following ACAG, the joint should be thoroughly cleaned by wire brushing.
Grinding of surfaces prior to welding is not required. If not welded, light grinding of the ACAG surface is
suggested.
3-7
CEMP-E
TI 809-26
1 March 2000
CHAPTER 4
STRUCTURAL STEELS
1. AISC AND AWS LISTED STRUCTURAL STEELS.
ED
a. AISC Approved Steels. For building-type structures, the AISC lists approved steels in Section A3.1
of the Specification for Structural Steel Buildings. Additional steels are listed in the AISC Seismic
Provisions for Structural Steel Buildings because of a more recent publication date. New structural steel
specifications have been developed and approved since publication, such as ASTM A992, and should
also be considered for application in structures. Structural steels currently accepted by AISC in the LRFD
Specification, or pending acceptance as noted, are as follows:
EL
L
Shapes and Plates
A36
A242
A2831
A514
A529
A572
A588
A709
A852
A9132
A9924 (wide flange shapes only)
AN
C
Rounds and Rectangular Sections
A53
A500
A501
A618
A8473
Sheet and Strip
A570
A606
A607
- added in AISC Seismic Provisions (1997)
-added in AISC LRFD Supplement (1998)
3
- added in AISC Hollow Structural Sections (1997)
4
- approved for next specification
C
1
2
b. AWS Prequalified Steels. AWS D1.1 lists prequalified steels in Table 3.1, and other approved
steels in Annex M. Prequalified steels have been determined to be generally weldable when using the
AWS D1.1 Code. For some steel specifications, only certain strength levels or grades are considered
prequalified. This situation may be because certain grades have compositional levels outside the range
considered readily weldable, because certain strength levels are less weldable, or because certain steels
or grades recently came into production and inadequate information was known about their weldability at
4-1
CEMP-E
TI 809-26
1 March 2000
the time of printing.
c. AWS Approved Steels. The steels listed in Annex M are approved for use, but Welding Procedure
Specifications (WPSs) must be qualified prior to use in welding these steels. These steels are generally
quenched and tempered steels, which are sensitive to temperature changes from welding operations that
may affect their strength, ductility, and toughness. They are also generally more sensitive to diffusible
hydrogen and are at higher risk of hydrogen-assisted HAZ cracking.
ED
d. Matching Filler Metals for Prequalified Steels. Table 4-1 provides a summary of structural steels
that are both approved by AISC and listed by AWS as prequalified. For joint designs requiring “matching”
filler metal, the “matching” filler metal for the given welding process is provided.
Table 4-1. AISC-Approved Structural Steels Prequalified under AWS D1.1 Table 3.1
AWS
Grou
p
Prequalified “Matching” Filler Metal
EL
L
Structural Steel
SMAW
A5.1: E60XX, E70XX
A5.5: E70XX-X1
AN
C
Shapes and Plates
A36
A529, grade 42
A709, grade 36
Round and Rectangular Sections
A53, grade B (round)
A500, grades A and B (round)
A500, grades A and B
(rectangular)
A501 (round)
C
I
FCAW
A5.20: E6XT-X, E6XT-XM
E7XT-X, E7XT-XM
(Except -2, -2M, -3, -10, -13, -14,
-GS)
A5.29: E6XTX-X1, E6XTX-X1M
E7XTX-X1, E7XTX-X1M
GMAW
A5.18: ER70S-X, E70C-XC, E70CXM
(Except -GS(X))
A5.28: ER70S-X1XX, E70C-X1XX
SAW
A5.17: F6XX-EXXX, F6XX-ECXXX
F7XX-EXXX, F7XX-ECXXX
A5.23: F7XX-EXXX-X1, F7XXECXXX1
4-2
CEMP-E
TI 809-26
1 March 2000
SMAW
A5.1: E70XX, low hydrogen
A5.5: E70XX-X1, low hydrogen
GMAW
A5.18: ER70S-X, E70C-XC, E70CXM
(Except -GS(X))
A5.28: ER70S-X1XX, E70C-X1XX
EL
L
Round and Rectangular Sections
A618, grades Ib, II, and III
(round)
FCAW
A5.20: E7XT-X, E7XT-XM
(Except -2, -2M, -3, -10, -13, -14,
-GS)
A5.29: E7XTX-X1, E7XTX-X1M
ED
II
Shapes and Plates
A572, grades 42 and 50
A588, 100 mm (4 in.) thick and
under
A709, grades 50 and 50W
A913, grade 50
SAW
A5.17: F7XX-EXXX, F7XX-ECXXX
A5.23: F7XX-EXXX-X1, F7XXECXXX1
Shapes and Plates
A572, grades 60 and 65
A913, grades 60 and 65
AN
III
C
SMAW
A5.5: E80XX-X1, low hydrogen
FCAW
A5.29: E8XTX-X1, E8XTX-X1M
GMAW
A5.28: ER80S-X1XX, E80C-X1XX
C
SAW
A5.23: F8XX-EXXX-X1, F8XXECXXX1
4-3
CEMP-E
TI 809-26
1 March 2000
SMAW
A5.5: E90XX-X1, low hydrogen
E9018M
GMAW
A5.28: ER90S-X1XX, E90C-X1XX
ED
IV
FCAW
A5.29: E9XTX-X1, E9XT-X1M
Shapes and Plates
A709, grade 70W
A852, grade 70
SAW
A5.23: F9XX-EXXX-X1, F9XXECXXX1
- except alloy groups B3, B3L, B4, B4L, B5, B5L, B6, B6L, B7, B7L, B8, B8L, B9
EL
L
1
C
AN
C
e. Matching Filler Metals for Non-prequalified Steels. Table 4-2 provides “matching” filler metal
information for structural steels approved by AISC, but not listed as prequalified by AWS D1.1.
Quenched and tempered steels are not listed in this table. With the exception of A992, the advice of a
competent welding consultant should be used prior to welding these steels. A992 steel is a new steel
specification which is essentially a more restricted A572, grade 50 steel.
4-4
CEMP-E
TI 809-26
1 March 2000
Table 4-2. AISC-Approved Structural Steels Not Prequalified under AWS D1.1 Table
3.1
Round and Rectangular Sections
A500, grade C (round)
Shapes and Plates
A242, all grades
A529, grades 50 and 55
A588, over 100 mm (4 in.)
A992, (W shapes only)
same as Table 4-1, Category I
Round and Rectangular Sections
A500, grade C (rectangular)
A618, grades Ib, II, and III
(round)
A847
same as Table 4-1, Category II
AN
C
NPQII
Shapes and Plates
A529, grade 46
A283, grade D (plates)
EL
L
NPQ-I
Suggested “Matching” Filler Metal
(Not Prequalified)
Structural Steel
ED
Grou
p
f. Unlisted Steels.
C
(1) Steels not listed as approved by AISC must be evaluated for structural properties such as yield
strength, tensile strength, ductility and toughness. AISC design specifications assume adequate strength
and ductility. For seismic applications, an assumed minimum level of toughness is assumed inherent
with the steels listed in AISC Seismic Provisions. Other steels may warrant CVN testing or other mill
documentation of typical toughness properties.
(2) Steels not listed as prequalified by AWS D1.1 must be evaluated for their weldability.
Weldability may be evaluated using methods such as carbon equivalency, the performance of WPS
qualification testing, or physical testing such as the Tekken test, Lehigh Restraint Cracking Test, or the
Varestraint Test. The Tekken and Lehigh methods simulate restraint that may be present in the actual
joint. See Appendix B, Weldability of Steels, Stout and Doty, for further information on these tests.
4-5
CEMP-E
TI 809-26
1 March 2000
2. WELDABILITY OF STRUCTURAL STEELS.
a. Chemical Composition. The chemical composition of the steel affects weldability and other
mechanical properties. Several elements are purposefully added in the production of structural steel, but
other undesirable elements may be present in the scrap materials used to make the steel. Carbon and
other elements that increase hardenability increase the risk of “cold” cracking, and therefore higher
preheat and interpass temperatures, better hydrogen control, and sometimes postheat are necessary to
avoid cold cracking.
ED
(1) Carbon (C) is the most common element for increasing the strength of steel, but high levels of
carbon reduce weldability. Carbon increases the hardenability of the steel, increasing the formation of
undesirable martensite with rapid HAZ cooling. Higher preheats and higher heat input welding
procedures may be needed when welding a steel with relatively high carbon contents. Typical steel
specifications limit carbon below 0.27%, but some steel specifications have much lower limits.
EL
L
(2) Manganese (Mn) is an alloying element that increases strength and hardenability, but to a
lesser extent than carbon. One of the principal benefits of manganese is that it combines with
undesirable sulphur to form manganese sulfide (MnS), reducing the detrimental effects of sulfur. With
high levels of sulfur, however, numerous large MnS inclusions may be present, flattened by the rolling
operation, increasing the risk of lamellar tearing when high through-thickness weld shrinkage strains are
created. Manganese limits are typically in the order of 1.40% or lower. A steel such as A36 does not
place limits on Mn content for shapes up to 634 kg/m (426 lb./ft.), or for plates and bars up to 20 mm (3/4
in.), inclusive.
C
(3) Phosphorous (P) is an alloying element that increases the strength and brittleness of steel.
Larger quantities of phosphorous reduce ductility and toughness. Phosphorous tends to segregate in
steel, therefore creating weaker areas. Phosphorous is typically limited to 0.04% to minimize the risk of
weld and HAZ cracking.
AN
(4) Sulfur (S) reduces ductility, particularly in the transverse direction, thereby increasing the risk of
lamellar tearing, and also reduces toughness and weldability. Higher sulfur levels will form iron sulfide
(FeS) along the grain boundaries, increasing the risk of hot cracking. Manganese is used to form MnS to
reduce this tendency. A minimum Mn:S ratio of 5:1 to 10:1 is recommended. Typical steel specifications
limit sulfur to 0.05%.
(5) Silicon (Si) is a deoxidizer used to improve the soundness of the steel, and is commonly used
to “kill” steel. It increases both strength and hardness. Silicon of up to 0.40% is considered acceptable for
most steels.
C
(6) Copper (Cu) is added to improve the corrosion resistance of the steel, such as in weathering
steels. Most steels contain some copper, whether specified or not. When specified to achieve
atmospheric corrosion resistance, a minimum copper content of 0.20% is required. Generally, copper up
to 1.50% does not reduce weldability, but copper over 0.50% may affect mechanical properties in heattreated steels.
(7) Nickel (Ni) is an alloying element used to improve toughness and ductility, while still increasing
strength and hardenability. It has relatively little detrimental effect upon weldability. Where nickel is
reported as a part of steel composition, it is generally limited to a maximum value between 0.25% and
0.50%.
4-6
CEMP-E
TI 809-26
1 March 2000
(8) Vanadium (V) is an alloying element used for increasing strength and hardenability. Weldability
may be reduced by vanadium. When vanadium is reported as a part of steel composition, vanadium is
generally limited to a maximum value between 0.06% and 0.15%.
(9) Molybdenum (Mo) is an alloying element which greatly increases hardenability and helps
maintain strength and minimize creep at higher temperature. When molybdenum is reported as a part of
steel composition, it is generally limited to a maximum value between 0.07% and 0.10%.
ED
(10) So-called “tramp” elements such as tin (Sn), lead (Pb), and zinc (Zn), may be present in steel
from the scrap material melted for steel-making. They have a low melting point, and may adversely
affect weldability and cause “hot” cracking. Other low-melting point elements that create a risk of hot
cracking include sulfur, phosphorous, and copper. When welding with high levels of these elements, it
may be necessary to use low heat input welding procedures to minimize dilution effects.
EL
L
b. Carbon Equivalency. The weldability of a steel can be estimated from its composition, using a
calculation system termed the carbon equivalent (CE). The most significant element affecting weldability
is carbon. The effects of other elements can be estimated by equating them to an additional amount of
carbon. The total alloy content has the same effect on weldability as an equivalent amount of carbon.
There are numerous carbon equivalent equations available and in use.
(1) The following equation is used in AWS D1.1 Annex XI.
CE = C + Mn/6 + Cr/5 + Mo/5 +V/5 + Ni/15 + Cu/15 + Si/6
C = carbon content (%)
Mn = manganese content (%)
Cr = chromium content (%)
Mo = molybdenum content (%)
V = vanadium content (%)
Ni = nickel content (%)
Cu = copper content (%)
Si = silicon content (%)
AN
C
Where
A carbon equivalent of less than 0.48 generally assures good weldability.
(2) Another common carbon equivalent equation is:
CE = C + Mn/6 + Cr/10 + Ni/20 + Cu/40 - V/10 - Mo/50.
C
If the CE from this equation is below 0.40, the material is considered readily weldable, and AWS D1.1
Table 3.2 guidance for the given steel strength should be adequate. For values between 0.40 and 0.55,
the use of preheat and low-hydrogen electrodes is generally necessary, regardless of thickness. Carbon
equivalent values above 0.55 indicate a high risk that cracks may develop unless special precautions are
implemented.
(3) The Dearden and O’Neill equation, applicable for steels with C greater than 0.12%, is similar:
CE = C + Cr/5 + Mo/5 + V/5 + Mn/6 + Ni/15 + Cu/15
A CE of 0.35% or lower is considered a steel with good weldability
4-7
CEMP-E
TI 809-26
1 March 2000
(4) For steels with C between 0.07% and 0.22%, the Ito and Bessyo equation may be used. The
Ito-Bessyo equation is also termed the composition-characterizing parameter, P cm.
CE = C + 5B + V/10 + Mo/15 + Mn/20 + Cu/20 + Cr /20 + Si/30 + Ni/60
Where
B = boron content (%)
ED
A CE of 0.35% or lower is considered a steel with good weldability.
(5) The Yurioka equation may also used to calculate CE for steel with C between 0.02% and
0.26%, as follows:
CE = C + A(C) * {5B + Si/24 + Mn/6 + Cu/15 + Ni/20 + Cr/5 + Mo/5 + Nb/5 + V/5}
Nb = niobium content (%)
A(C) = 0.75 + 0.25 * tanh [ 20 (C- 0.12) ]
C
AN
C
EL
L
Where
4-8
CEMP-E
TI 809-26
1 March 2000
Table 4-3. Chemical Requirements for Sample Structural Steels
(heat analysis, %, maximum, unless range is provided)
A572
grade 50
(shapes)
Type 1
A572
grade 50
(shapes)
Type 2
C
0.26
0.23
0.23
Mn
---
P
0.04
S
0.05
Si
0.40
Cu
#
Compositio
n
V
A588,
grade B
A852
0.23
0.20
0.19
1.35
1.35
0.50-1.50
0.75-1.35
0.80-1.35
0.04
0.04
0.035
0.04
0.035
0.05
0.05
0.045
0.05
0.04
0.40
0.40
0.40
0.15-0.50
0.20-0.65
#
#
0.60
0.20-0.40
0.20-0.40
0.01-0.15
0.11
0.01-0.10
0.02-0.10
-----
0.0050.05
---
0.05
---
---
Ni
---
---
---
0.45
0.50
0.50
Cr
---
---
---
0.35
0.40-0.70
0.40-0.70
Mo
---
---
---
0.15
---
---
C
AN
Co
A992
EL
L
A36
(shapes)
C
Steel
ED
(Refer to ASTM specifications for complete information, including applicable
thickness ranges, grades, types, combinations of elements, etc.)
Shapes composition limits are listed for sections up to 634 kg/m (426 plf).
# minimum 0.20% when specified
3. PROPERTY ENHANCEMENTS FOR STRUCTURAL STEELS.
a. Yield to Ultimate Strength Ratio. AISC design equations assume some margin in structural steel
from the point of yielding to the point of fracture to allow for the redistribution of stress. Some structural
steels have been produced with F y:Fu ratios as high as 0.95, considerably higher than that considered by
4-9
CEMP-E
TI 809-26
1 March 2000
AISC in developing design methodologies.
(1) ASTM A572, grade 50, manufactured to the supplemental requirements of AISC Technical
Bulletin #3, provides a requirement for a maximum F y:Fu ratio of 0.85. This same value is a requirement
for ASTM A992 steels. Although not considered critical in low-seismic applications, this requirement is
advisable for members in the lateral load resisting systems in high-seismic applications.
ED
(2) Structural steels providing this maximum F y:Fu ratio are readily available from mill sources.
Such a requirement can be met by special mill order requirements, the specification of A572, grade 50
meeting AISC Technical Bulletin #3, the specification of A992 shapes, or through the review of mill test
reports of existing steels in inventory that are traceable to the mill heat number. There is currently no
premium in steel mill cost to specify such properties, but some minor delays may be encountered in
purchasing until the inventory of such materials is predominant.
EL
L
b. Killed Steel. Killed steel has been processed to remove or bind the oxygen that saturates the
molten steel prior to solidification. ASTM A6 / A6M defines killed steel as “steel deoxidized, either by
addition of strong deoxidizing agents or by vacuum treatment, to reduce the oxygen content to such a
level that no reaction occurs between carbon and oxygen during solidification.” Semi-killed steel is
incompletely deoxidized, and may also be specified.
(1) The benefit of killing is to reduce the number of gas pockets present in the steel, which can
adversely affect the mechanical properties of the steel, including ductility and toughness, as well as
reduce the number of oxide-type inclusions in the steel.
(2) Most mills provide some form of deoxidation, in the form of semi-killed steel, as a part of
routine production practices. AISC does not require killed steel for any specific applications.
C
(3) Most commonly, killing is done using additions of silicon, but may also be done with aluminum
or manganese. Killed steels often have silicon levels in the range of 0.10% to 0.30%, but may be higher.
AN
(4) Project requirements for killed steel should be considered when using wide-flange sections in
Groups 4 or 5, and plates when over 50 mm (2 inches) in thickness, in tension applications, which have
special AISC requirements for toughness in AISC Specification section A3.1c. ASTM A992 requires the
steel to be killed.
C
(5) Specifying killed or semi-killed steel may carry a slight cost premium, except in the case of
A992 steel. Because killed steel is typically a cost-premium mill order item, the inventory of killed
structural steels available at steel service centers and in steel fabricating plants is less than that of
regular steels. Mill orders typically require longer production lead times than service center or stock
items.
c. Fine Grain Practice. Fine grain practice is the method of achieving Fine Austenitic Grain Size,
defined by ASTM A6 / A6M as grain size number 5 or higher, measured using test methods prescribed
by ASTM E112. Aluminum is typically used to achieve fine grain practice, which binds oxygen and
nitrogen. When aluminum content is above 0.20%, by heat analysis, the steel is considered fine-grained,
without the need for testing.
(1) Fine grain practice is beneficial in improving ductility and toughness. Consideration of
requirements for fine grain practice should be made when using wide-flange sections in Groups 4 or 5,
and plates when over 50 mm (2 inches) in thickness, in tension applications, which have special AISC
4-10
CEMP-E
TI 809-26
1 March 2000
requirements for toughness in AISC Specification section A3.1c. When specifying steel to fine grain
practice, ASTM Supplementary Requirement S91 should be consulted for the specific steel grade.
(2) Because fine grain practice is typically a cost-premium mill order item, the inventory of
structural steels available at steel service centers and in steel fabricating plants manufactured to fine
grain practice is less than that of regular structural steel. Mill orders typically require longer production
lead times than service center or stock items.
ED
d. Toughness. Steel toughness, also commonly referred to as “notch toughness”, is the resistance to
brittle crack initiation and propagation. For this resistance, the steel must have sufficient plastic ductility
to redistribute stresses at the root of a notch to the surrounding material. Toughness may be measured
using a variety of methods, but the steel industry standard is the Charpy V-Notch (CVN) method, as
prescribed by ASTM A370. CVN testing is an added charge by the steel producer, and steel with CVN
testing is not routinely ordered by steel service centers or steel fabricators for inventory. Therefore,
steels with CVN testing are generally available only through mill order, which typically requires longer
production lead times than service center or stock items.
C
EL
L
e. Improved Through-thickness Properties. For certain high-restraint applications subject to the risk of
lamellar tearing, steels with improved through-thickness properties may be specified. The most common
method of improving through-thickness properties, to reduce the risk of lamellar tearing, is through the
specification of low-sulfur or controlled sulfur-inclusion steels. By reducing the sulfur content, the number
and size of manganese sulfide (MnS) inclusions is reduced. Typically, low-sulfur steels in plate form can
be ordered to 0.005% sulfur, at a cost premium and with longer lead time. Most steel specifications
permit maximum sulfur in amounts between 0.30% to 0.50%. Shapes are not routinely available with
substantially reduced sulfur levels, and would be available only at substantial cost premium and
considerable delay. However, a mill may be able to select heats of steel with particularly lower levels of
sulfur for rolling specific sections. It is also possible to specify through-thickness tensile testing using
reduction of area as the governing criteria, but this is rarely necessary.
AN
f. Normalizing. Normalizing is defined in ASTM A6 / A6M as “a heat treating process in which a steel
plate is reheated to a uniform temperature above the critical temperature and then cooled in air to below
the transformation range.” In practice, steel is heated to approximately 900 oC to 930oC (1650oF to
1700oF). The benefits include refined grain size and uniformity, improved ductility and improved
toughness. Few building applications warrant the need for normalized steel. The specification of
normalized steel is a mill order item only, an added expense with added time for delivery from the steel
mill. Normalized steel is not routinely available from steel service centers or stocked by fabricators.
C
4. SELECTION OF STRUCTURAL STEELS FOR ENVIRONMENTAL EXPOSURE AND SERVICE
APPLICATIONS.
a. High-seismic Applications. The AISC Seismic Provisions, Section 6.3, require steel in the Seismic
Force Resisting System to have a minimum toughness of 27J at 21 oC (20 ft.-lb. at 70oF), applicable to
ASTM Group 4 and 5 shapes, Group 3 shapes with flanges 38 mm (1-1/2 in.) or thicker, and to plates in
built-up members 38 mm (1-1/2 in.) or thicker. Studies indicate that a large percentage of domestically
produced structural steel sections lighter or thinner than those mentioned in the previous paragraph will
have a CVN toughness of at least 27J at 21 oC (20 ft.-lb. at 70oF), and therefore it does not appear that
CVN testing need be conducted to verify the toughness of all members. It is recommended that
manufacturer’s accumulated data be used to verify that the steel routinely produced by that mill meets
the indicated toughness levels. Specification of steel toughness levels, or the specification of A709
4-11
CEMP-E
TI 809-26
1 March 2000
steels, is currently considered unnecessary for ordinary building-type applications.
C
AN
C
EL
L
ED
b. Fatigue Applications. Toughness requirements should be considered for applications involving
fatigue. As a guide, the toughness values specified in ASTM A709 / A709M, Table S1.1 and S1.2,
summarized and adapted in Table 4-4, may be used for redundant fatigue applications. Modifications to
this table are suggested for steels that have yield strengths 103 MPa (15 ksi) or more above the
minimum specified yield strengths, for all but A36 steels. See the ASTM A709 / A709M specification for
appropriate changes to the testing temperatures for these cases. For nonredundant fatigue applications,
see ASTM A709 / A709M, Table S1.3 for guidance. The required CVN toughness and testing
temperature may be specified directly in the specifications for the project, to be placed on the mill order.
Alternatively, a given ASTM A709 / A709M steel and temperature zone may be specified.
4-12
CEMP-E
TI 809-26
1 March 2000
Table 4-4. Toughness Guidelines for Structural Steel in Fatigue Applications,
Redundant Applications.
Applicatio
n
Minimum Service Temperature
Steel
Thickness
A36
to 100 mm (4
in.), incl.
bolted or
welded
20J @ 21oC
(15 ft-lbf @
70oF)
A572, gr
50
A588
to 50 mm (2
in.), incl.
bolted or
welded
20J @ 21oC
(15 ft-lbf @
70oF)
“
over 50 to
100 mm (2 in
to 4 in.)
bolted
20J @ 21oC
(15 ft-lbf @
70oF)
20J @ 4oC
(15 ft-lbf @
40oF)
20J @ -12oC
(15 ft-lbf @
10oF)
“
over 50 to
100 mm (2 in
to 4 in.)
welded
20J @ 21oC
(20 ft-lbf @
70oF)
20J @ 4oC
(20 ft-lbf @
40oF)
20J @ -12oC
(20 ft-lbf @
10oF)
A852
to 65 mm (21/2 in.), incl.
bolted or
welded
27J @ 10oC
(20 ft-lbf @
50oF)
27J @ -7oC
(20 ft-lbf @
20oF)
27J @ -23oC
(20 ft-lbf @ 10oF)
over 65 mm
to 100 mm (21/2 in to 4 in.)
bolted
27J @ 10oC
(20 ft-lbf @
50oF)
27J @ -7oC
(20 ft-lbf @
20oF)
27J @ -23oC
(20 ft-lbf @ 10oF)
over 65 mm
to 100 mm (21/2 in to 4 in.)
welded
34J @ 10oC
(25 ft-lbf @
50oF)
34J @ -7oC
(25 ft-lbf @
20oF)
34J @ -23oC
(25 ft-lbf @ 10oF)
to 65 mm (21/2 in.), incl.
bolted or
welded
34J @ -1oC
(25 ft-lbf @
30oF)
34J @ -18oC
(25 ft-lbf @
0oF)
34J @ -34oC
(25 ft-lbf @ 30oF)
“
over 65 mm
to 100 mm (21/2 in to 4 in.)
bolted
34J @ -1oC
(25 ft-lbf @
30oF)
34J @ -18oC
(25 ft-lbf @
0oF)
34J @ -34oC
(25 ft-lbf @ 30oF)
“
over 65 mm
to 100 mm (21/2 in to 4 in.)
welded
48J @ -1oC
(35 ft-lbf @
30oF)
48J @ -18oC
(35 ft-lbf @
0oF)
48J @ -34oC
(35 ft-lbf @ 30oF)
“
C
A514
Zone 2
-34oC (-30oF)
4-13
Zone 3
-51oC (-60oF)
20J @ -12oC
(15 ft-lbf @
10oF)
20J @ 4oC
(15 ft-lbf @
40oF)
20J @ -12oC
(15 ft-lbf @
10oF)
ED
20J @ 4oC
(15 ft-lbf @
40oF)
EL
L
C
AN
“
Zone 1
-18oC (0oF)
CEMP-E
TI 809-26
1 March 2000
EL
L
ED
c. Cold Weather Applications. Steel toughness requirements should be considered for major loadcarrying components of structures exposed to extreme cold environments. When structural components
in a low-temperature environment are not subject to significant impact loads or fatigue conditions, it is
generally more cost effective to specify a type of steel with inherently good fracture toughness, and
avoid a requirement for specific CVN toughness at a reference temperature. High-strength low alloy
(HSLA) steels that are manufactured using fine grain practice have improved toughness at low
temperature, compared to conventional carbon steels such as A36 steel. AISC-approved steels requiring
production to fine-grain practice are A588, A709 (grades 50W, 70W, 100, 100W), A852, and A913
(grades 60, 65 and 70), although higher strength structural steels present additional welding difficulties
and should not be specified unless necessary for weight savings. Fine-grain practice can optionally be
specified using ASTM Supplemental Requirement S91 for A36, A572, A992, A709 (grades 36 and 50),
and A913 (grade 50). It is not available for A529, A242, or A283 steels. Steels that require killing, which
also improves toughness, include A992 and A709 (grades 100, 100W), but the higher strength grades
should be avoided because of other welding difficulties. Nitrogen has a significant effect upon CVN
transition temperatures, and limitations on nitrogen may be considered. A992 steels place a limit on
nitrogen of 0.012%, unless nitrogen binders are added. A572, Type 4 steel has a limit on nitrogen of
0.015%.
AN
C
d. High Stress / Strain / Restraint Applications. When welded joints are made to the side of a member,
creating through-thickness shrinkage stresses and strains, consideration should be made for the risk of
lamellar tearing. Lamellar tearing is a separation or tearing of the steel on planes parallel to the rolled
surface of the member. There is no specific through-thickness at which lamellar tearing will or will not
occur, nor specific values for weld size, stresses or strains that will induce tearing. Generally, lamellar
tearing is avoided through using one or more of the following techniques: improved design or redesign of
the joint, welding procedure controls, weld bead placement selection, sequencing, the use of preheat
and/or postheat, the use of low-strength, high-ductility filler metals, “buttering,” and peening. However,
steels with improved through-thickness properties may also be specified. The most common method of
improving through-thickness properties, to reduce the risk of lamellar tearing, is through the specification
of low-sulfur or controlled sulfur-inclusion steels. See 3.e.
C
5. AVAILABILITY OF STRUCTURAL STEELS. All AISC-approved structural steels are available from
domestic steel mills, with the exception of A913. The AISC Manual of Steel Construction, Table 1-1,
provides general information regarding availability of shapes, plates and bars in various steel
specifications, grades and strengths. Table 1-4 provides similar information for round and rectangular
sections, including availability as either steel service center stock or in mill order quantities only. Table 13 lists the producers of specific structural shapes, and Table 1-5 provides similar information for round
and rectangular sections. This list is updated semi-annually in Modern Steel Construction magazine,
published by AISC, in the January and July issues.
4-14
CEMP-E
TI 809-26
1 March 2000
CHAPTER 5
DESIGN FOR WELDING
1. GENERAL.
2. GOOD DESIGN PRACTICE.
EL
L
ED
a. Engineer’s Responsibility. The Engineer is responsible for the analysis and design of the
connection, including connections between elements in built-up members. Critical structural steel
connections must be completely detailed and shown on the contract drawings. The Engineer may
prescribe connection details, if desired or necessary, but generally it is best to allow the fabricator or
erector to select the specific welding detail to be used for a particular joint. For instance, it may be
adequate for the Engineer to specify a Complete Joint Penetration (CJP) groove weld, or specify a
Partial Joint Penetration (PJP) groove weld and state the required throat. This may effectively be done
through the use of AWS welding symbols, and when necessary for prequalified groove welds, the
appropriate AWS designation. The fabricator and erector are typically in the best position to select which
process, groove type (single, double, bevel, vee, J, U), and groove angle should be used based upon
economics, availability of equipment and personnel, distortion control, and ease of welding operations.
The Engineer must review and approve the final details selected by the contractor.
AN
C
a. Availability of Materials, Equipment and Personnel. In the selection of base metals, welding
processes, filler metals, and joint designs, one should consider the availability of the structural steel,
welding equipment, filler metals, personnel qualified to perform such welding, personnel qualified to
inspect the welding, and NDT equipment and personnel necessary to perform NDT as required. Certain
welded joint designs may require notch-tough filler materials, welding personnel qualified in out-ofposition welding, welders qualified for specific processes, enclosures for field welding, or nondestructive
testing. When the availability of any of the above is in question, alternative joint designs should be
investigated.
b. Access. The following items should be considered to permit welding operations to be made with
adequate quality:
(1) Welding personnel must have direct visual access to the root of the weld. All passes must be
visually monitored by the welder during welding.
C
(2) Access should be adequate so that the welding electrode can be positioned at the proper angle
for proper penetration and fusion. Generally, the electrode should be positioned so that the angle
between the part and the electrode is not less than 30 o. Smaller angles may cause a lack of fusion along
the weld / base metal interface. Access should be checked at the design stage when welding in highly
confined spaces or with closely spaced parts.
(3) Weld access holes, placed in beam and girder webs when splicing flanges or making beam-tocolumn moment connections, must be of adequate size to permit the weld to be placed by reaching
through the access hole with the electrode. Minimum access hole sizes are specified in AWS D1.1
Figure 5.2. Larger access holes may be warranted based upon the welding process and type of welding
equipment used.
5-1
CEMP-E
TI 809-26
1 March 2000
(4) Narrow root openings and narrow groove angles inhibit access to the joint root, contributing to
lack of penetration at the root and lack of fusion along the joint sidewalls. Proper joint design, preferably
using joints prequalified under AWS D1.1 should be used.
EL
L
ED
c. Position. It is preferred to weld in the flat position when making groove welds, plug welds or slot
welds, and in either the flat or horizontal positions when making fillet welds. Welding positions are
defined in AWS D1.1 in Figure 4.1 for groove welds and in Figure 4. 2 for fillet welds. To assist in
interpreting the positions given, see AWS D1.1 Figure 4.3 for groove welds, Figure 4.5 for fillet welds,
and Figures 4.4 and 4.6 for tubular joints. Welding in other than the flat or horizontal positions increases
welding time approximately four-fold, on average, increasing cost and construction time. Fewer welding
personnel are qualified by test to perform welding out-of-position. Although personnel may be previously
qualified by test to weld out-of-position, a welder may not have recently used the special techniques and
procedures for welding in these positions, and therefore may have lost some of the skill necessary to
perform quality out-of-position welding. In this case, close visual observation of the welder during the first
few out-of-position passes is especially important, and requalification testing may be necessary. The
quality of out-of-position welds is more difficult to maintain, and they typically do not have the smooth
appearance of welds performed in the flat or horizontal positions. This makes visual inspection and some
forms of NDT more difficult.
d. Joint Selection. For guidance in the selection of groove details that provide sufficient access,
limited distortion, and cost-effectiveness, the prequalified groove weld details in AWS D1.1 Figures 3.3
and 3.4 should be reviewed. The following items should be considered in selecting or evaluating joint
selection:
AN
C
(1) For butt joints, partial joint penetration (PJP) groove welds are more economical than complete
joint penetration (CJP) groove welds. Provided CJP groove welds are not required by Code for the given
application or for fatigue and seismic applications, PJP groove welds should be considered for tensionand shear-carrying joints when full strength of the connected members is not required, and for
compression splices such as column splices. PJP groove welds are prepared to a required depth of
chamfer, usually the required effective throat, or 3 mm (1/8 in.) deeper, depending upon groove angle,
welding process and position.
(2) For most applications, by Code, CJP groove welds require the use of either backing bars, which
may need to be removed in certain types of joints, or removal of a portion of the root pass area by
backgouging followed by backwelding until the joint is complete. In addition, more welding is required to
join the entire thickness of material, rather than just the amount of welding needed to carry the load.
C
(3) In butt joints, V-groove welds are preferred over bevel-groove welds. Bevel-groove welds are
generally more difficult to weld, especially when the unbeveled face is vertical, and lack of fusion on the
unbeveled face may result. V-groove welds, because they are balanced and usually have a downhand
position on each groove face, are easier to weld. Access to the root is also easier to achieve because of
the balance and the wider groove angle used.
(4) For tee joints, fillet welding is generally less expensive than groove welding, until the fillet size
reaches approximately 16 to 20 mm (5/8 to 3/4 in.). Above this size, PJP groove welding, or a
combination groove weld with reinforcing fillets, should be considered. There is added expense in joint
preparation for groove welds that is not required with fillet welds, however, there may be offsetting cost
savings with groove welds because of decreased weld volume, fewer passes, and therefore less labor
and materials. Less distortion may also be incurred because of the reduced weld volume.
5-2
CEMP-E
TI 809-26
1 March 2000
(5) Square groove welds have limited application for structural steel. They are better suited for thin
materials. When square groove welds are used, the root opening must be closely controlled and the
Welding Procedure Specification (WPS) closely developed and followed.
ED
(6) For thick materials, generally starting at thicknesses of 50 mm (2 in.), J- and U-groove welds
may be more economical than bevel- and V-groove welds. The wider root initially requires more weld
metal, but the narrower groove angle reduces the total weld volume below that of bevel- and V-groove
welds. There are also higher initial joint preparation costs to prepare a J- or U-groove joint, so even more
weld metal must be saved to recover these costs. When angular distortion or shrinkage strains must be
minimized, J- and U-groove joints should be considered. The reduced groove angle minimizes the
differential in weld width from top to bottom of the joint.
(7) Root opening widths should be generous but not excessive. Wider root openings allow for
complete penetration to the bottom of the joint preparation. However, very wide roots contribute to root
pass cracking and root HAZ cracking from weld shrinkage. Narrow root openings contribute to lack of
penetration, lack of fusion, and trapped slag at the root.
EL
L
(8) Groove angles should be the minimum angle that will provide adequate access for penetration
to the root, and adequate access to the groove faces for complete fusion. Excessively wide groove
angles contribute to added angular distortion, increased risk of shrinkage cracking, increased risk of
lamellar tearing in T-joints, and higher costs because of the additional material and labor used.
AN
C
e. Prequalified Joint Details. The prequalified groove weld details in AWS D1.1 Figure 3.3 for Partial
Joint Penetration (PJP) groove welds, and Figure 3.4 for Complete Penetration Joint (CJP) groove
welds, provide root opening, groove angle, root face, thickness limits, tolerances, and other information
for the effective detailing of groove welds. Root openings and groove angles are considered adequate for
the welding processes and positions noted, without causing excessive angular distortion. For PJP groove
welds, the required depth of preparation is provided to achieve the desired effective throat. When the
joint details as shown are used, qualification testing of the joint detail is not required to verify the
suitability of the detail, provided other prequalification provisions of the Code are also met. See AWS
D1.1 Section 3 for these limits. The use of prequalified groove weld details does not guarantee that
welding problems will not occur. The details may not always be the best detail, and other more efficient,
cost-effective or easier-to-weld details may be used. However, when other groove details are used,
qualification testing is required.
C
f. Qualified Joint Details. Groove weld details may be used other than those shown as prequalified in
AWS D1.1 Figures 3.3 and 3.4. Alternate details may be selected with reduced or wider root openings,
reduced or wider groove angles, or other revised details. Generally, narrower root openings and groove
angles increase the risk of incomplete penetration at the root and lack of fusion along the groove faces.
These problems may be minimized through the use of suitable WPSs. Qualification testing, as
prescribed in AWS D1.1 Section 4, is required in such cases to verify the ability of the WPS to provide
the penetration and quality necessary.
g. Distortion. Angular distortion can be minimized through the use of double-sided welding, the use of
minimum groove angles, J- or U-groove welds, presetting of parts, and WPS selection. Double-sided
welds balance weld shrinkage about the center of the part’s cross-section. When the part can be
frequently rotated for welding on opposite sides, a balanced groove detail can be used. When one side
will be welded in its entirety before proceeding to weld the opposite side, the first side groove depth
should be approximately 35-40% of the total groove depth of both welds. The completed first side weld
restrains the second side weld from shrinking as much as the unrestrained first-side weld. Minimum
5-3
CEMP-E
TI 809-26
1 March 2000
groove angles and J-and U-groove details reduce the difference in weld width between the root and the
face of the weld, and therefore reduce the weld shrinkage.
3. DESIGN AND FABRICATION OF WELDED JOINTS.
a. Effective Weld Size / Throat. AWS D1.1 Section 2, Part A provides the details for the calculation of
effective weld size, also called effective throat, and effective weld length.
ED
(1) Complete Joint Penetration (CJP) groove welds have an effective throat equal to the thickness
of the thinner part joined.
(2) Partial Joint Penetration (PJP) groove welds must have their size specified in the design, and
then be detailed to provide the throat required. AWS provides the required depth of preparation for PJP
groove welds in D1.1, Figure 3.3. AISC provides similar information in Table J2.1.
EL
L
(3) For flat and convex fillet welds, the effective size is specified in terms of weld leg, but the
effective throat is the shortest distance from the root to a straight line drawn between the two weld toes.
Should the fillet weld be concave, the measurement of leg size is ineffective, and the throat must be
measured as the shortest distance from the root to the weld face.
C
b. Allowable Stresses / Design Strengths. Allowable weld stress, when using ASD, is provided in AWS
D1.1 Table 2.3, or in AISC Table J2.5 of the ASD Specification. Weld design strength (when using
LRFD) is provided in AISC Table J2.5 of the LRFD Specification. Both AWS and AISC tables are
similarly structured, with minor differences in certain sections. The following information is in terms of
LRFD, without consideration of the resistance factor phi. If ASD is used, see the appropriate
specification.
AN
(1) For welds other than CJP groove welds loaded in transverse tension, the AWS D1.1 Code
permits the use of matching filler metal or a filler metal of lower strength. Overmatching is not permitted
in AWS D1.1. AISC permits the use of undermatching for the same conditions, and also overmatching
filler metal to the extent of one weld strength classification, nominally 70 MPa (10 ksi) more.
(2) For CJP groove welds that carry transverse tensile stress, the AWS D1.1 Code requires the use
of matching filler metal. Matching filler metal provides a weld with at least the strength of the base metal
in such an application. See AWS D1.1 Table 3.1 for matching filler metals. The strength of the weld is
treated the same as the strength of the base metal, as the base metal will be the weaker of the two
materials, with a phi of 0.9.
C
(2) Should the CJP groove weld be used in a T-joint or corner joint loaded in tension transverse to
its axis, with the backing bar remaining in place, AISC LRFD Specification Table J2.5, Note [d] requires
the use of filler metal with a designated CVN toughness of 27J @ +4 oC (20 ft.-lbf @ +40oF).
Alternatively, the weld must be designed as a PJP groove weld, similarly loaded.
(3) For CJP groove welds in transverse compression, the AWS D1.1 Code requires the use of
either matching filler metal or a filler metal one strength classification less, nominally 70 MPa (10 ksi)
less. AISC places no limit on the undermatching strength. The strength of the weld is treated the same as
the strength of the base metal, with a phi of 0.9.
(4) CJP groove welds in shear may carry 0.60 times the classification strength of the filler metal,
5-4
CEMP-E
TI 809-26
1 March 2000
with a phi of 0.8.
(5) CJP groove welds and other welds carrying tension or compression parallel to the axis of the
weld need not be designed for the tensile or compressive stress, only for any shear forces that may be
transferred between the connected parts. As an example, girder web-to-flange welds need not be
designed for the axial force from bending, only for the shear transferred between the web and flange.
ED
(6) PJP groove welds in transverse tension are permitted to carry 0.60 times the classification
strength of the filler metal, with a phi of 0.8. The stress on the base metal is also limited to the minimum
specified yield strength of the base metal, with a phi of 0.90, using the effective size (throat) of the
groove weld for the check of the base metal stress.
EL
L
(7) PJP groove welds in compression are currently treated differently by AWS and AISC. Under
AWS D1.1, PJP groove welds are categorized into joints designed to bear and joints not designed to
bear. AISC, because it is based upon new construction, provides design values only for the joint
designed to bear application. Under AISC, for joints designed to bear, the weld stress need not be
checked, as the base metal will govern the strength of the joint, with a phi of 0.9.
(8) For joints not designed to bear, only AWS provides design values, based upon Allowable
Stress Design (ASD). The weld stress may not exceed 0.50 times the classification strength of the filler
metal, and the base metal stress may not exceed 0.60 times the minimum specified yield strength of the
base metal, applied to the throat of the groove weld. LRFD values, considering the factor phi, are
generally 1.5 times the ASD values.
(9) PJP groove welds in shear may be stressed to 0.60 times the classification strength of the filler
metal, with a phi of 0.75.
AN
C
(10) Fillet welds may be stressed to 0.45 times the classification strength of the filler metal, with a
phi of 0.75. There is no need to check the shear stress in the base metal along the diagrammatic leg of
the fillet weld. Research indicates that, because of penetration and HAZ hardening, the leg of the fillet
weld is not a failure plane that needs checked.
(11) For transversely loaded fillets welds, AWS D1.1 Section 2.14.4 and 2.14.5, and AISC LRFD
Specification Appendix J2.4, permit a 50% increase in the allowable shear stress on the weld. For angles
other than transverse, an increase is also permitted based upon an equation. For eccentrically loaded
fillet weld groups, allowable shear stress increases are also permitted when using the instantaneous
center of rotation approach for the analysis of the weld group. Design values for typical weld groups are
provided in the AISC Manual.
C
(12) When fillet weld strength increases, as above, are used for loading other than parallel to the
weld axis, AISC LRFD Specification Table J2.5, Note [h] requires the use of CVN toughness as above.
(13) When a fillet weld is loaded longitudinally along its axis, and is loaded from its end, as in a
splice plate or brace member, there is a maximum effective length of 100 times the leg size before a
reduction factor must be implemented. Longer fillet welds loaded in such a manner must be analyzed
using a reduction coefficient Beta from AISC LRFD Specification equation J2-1. The maximum effective
length is 180 times the leg size, which would apply when the weld is 300 times the leg size in length, with
a reduction coefficient Beta of 0.6.
(14) Plug and slot welds may be stressed to 0.60 times the classification strength of the filler metal,
5-5
CEMP-E
TI 809-26
1 March 2000
with a phi of 0.75. There is no need to check the stress in the base metal along the base of the plug or
slot. Plug and slot welds may be designed only for shear forces along the base of the hole or slot, not for
shear along the walls of the hole or slot.
ED
(15) With shear stress in any type weld, the Code requires a check of the base metal in shear,
limiting the base metal stress to 0.60 times the minimum specified yield strength of the base metal, with
a phi of 0.75. This check is applied to the thickness of the material, not the weld/steel interface, to verify
that the steel has the capacity to carry the load delivered to or from the weld. This is especially
applicable to situations using fillet welds on opposite sides of thin beam and girder webs.
EL
L
c. Minimum Weld Size. Minimum weld sizes are incorporated into both the AWS D1.1 and AISC
codes. AWS D1.1 Table 5.8, provides minimum fillet weld sizes, and Table 3.4 provides minimum
prequalified PJP groove weld sizes. The basis of these tables is the need to slow the cooling rate when
welding on thicker materials. Small welds provide little heat input to the thick base metal, which acts as
an efficient heat sink, and therefore the weld region cools very rapidly. The rapid cooling creates a hard,
martensitic heat-affected zone (HAZ), with potentially high levels of trapped hydrogen, with a higher risk
of cracking. Larger welds are made with higher welding heat input, therefore reducing the cooling rate,
and reduce the risk of HAZ cracking to acceptable levels. AISC Table J2.3 provides minimum fillet weld
sizes similar to AWS D1.1 Table 5.8, but does not provide weld size reductions based upon the use of
low hydrogen electrodes or preheat.
C
d. Maximum Fillet Weld Size. A maximum fillet weld size is established for lap joints where a fillet
weld is placed along the edge of a part. The maximum fillet weld size that should be specified, when the
part is 6 mm (1/4 in.) or more in thickness, is 2 mm (1/16 in.) less than the thickness of the part. This is
to protect the edge of the part from melting under the arc, making it difficult to verify adequate leg size
and throat. For lap joints where the part receiving the fillet weld along its edge is less than 6 mm (1/4 in.)
in thickness, the specified fillet weld size may equal the thickness of the part. See AWS D1.1 Section
2.4.5.
AN
e. Available Design Aids. Design aids for welded connections, in the form of tables and software, are
available. See Appendix B, Bibliography.
C
f. Weld Access Holes. Weld access holes provide access for welding equipment to reach the weld
region, reducing the interference from the member itself. They also provide access for weld cleaning and
inspection. Access holes also serve to separate weld shrinkage stresses when fully welded joints are
made in both the member web and flange, as an example. Typically, weld access holes are provided in
beam and girder webs when splicing flanges, or when making welded flange connections in beam-tocolumn joints, but may also be used in other joints where interferences exist. See AWS D1.1 Section
5.17, and AISC LRFD Specification Section J1.6 for minimum access types, dimensions, and quality.
When weld access holes are used in heavy sections or high-seismic applications, special provisions
regarding surface quality and inspection apply.
g. Reentrant Corners. Reentrant corners are internal cuts in members. Typical reentrant corners in
buildings are found at openings for piping and ductwork in beam webs. Reentrant corners must be
smooth, with no notches, with a minimum radius of 25 mm (1 in.). Grinding of reentrant corners and
tangency is not required. Beam copes and weld access holes are treated separately by the code. See
AWS D1.1 Section 5.16.
h. Heavy Section Joint Provisions. Under the AISC LRFD Specification, special material, welding and
quality requirements apply for applications using ASTM Group 4 and 5 shapes, and for built-up sections
5-6
CEMP-E
TI 809-26
1 March 2000
EL
L
ED
using plates over 50 mm (2 in.) in thickness. AWS D1.1 provisions apply for ASTM Group 4 and 5
shapes and for built-up sections with a web plate over 38 mm (1-1/2 in.) in thickness. Both codes apply
these provisions only when the materials are used with welded tensile splices, but have also been
applied to connections such as beam-to-column connections where the flanges are direct-welded for
moment resistance. The special material requirements include a minimum CVN toughness taken from a
specific, nonstandard location in the material. The special provisions listed do not apply when the joint
carries only compression, such as column splices, or when bolted slices are used. Weld access holes
must be preheated to 65 oC (150oF) prior to thermal cutting, ground to bright metal, and inspected using
either Penetrant Testing (PT) or Magnetic Particle Testing (MT). Optionally, weld access holes may be
made by drilling and saw-cutting, but PT or MT of the cut surface is still required. For joint welding,
minimum preheat and interpass temperature of 175 oC (350oF) must be used, higher than that required by
AWS D1.1 Table 3.2. Weld tabs and backing bars must be removed after completion of the joint. AWS
D1.1 code provisions contain most, but not all, of these provisions. The AISC ASD Specification does not
contain the latest joint details, and therefore AISC LRFD Specification provisions should be used. See
AISC section A3.1c for materials requirements, J2.8 for preheat requirements, J1.6 for access hole
requirements, and J1.5 for weld tab and backing bar removal requirements. See AISC LRFD Figure CJ1.2 for dimensional and fabrication requirements for weld access holes.
C
i. Backing Bars. Backing bars are used to close and support the root pass of groove welds when made
from one side of the joint. Joint assembly tolerances are greater when backing bars are used, compared
to joints without backing. Assembly tolerances without backing are typically within 3 mm (1/8 in.), difficult
to achieve with structural steel sections in either the shop or field, but possible for some types of joints
for shop fabrication. With backing, the assembly tolerances are typically enlarged to allow variations of 8
mm (5/16 in.). Welding is more easily performed with backing to support the root pass, eliminating
concerns for melt-through and repair. In some joints, particularly in fatigue and seismic applications, it
may be recommended or necessary to remove the backing bar after use. This adds cost to the operation,
particularly when rewelding and / or finishing of the removed area is necessary.
AN
(1) Steel backing is used almost universally in steel construction. Those applications that require
subsequent backing removal are sometimes done with nonfusible backing materials such as copper,
ceramic or flux. The use of backing materials other than steel is generally considered nonprequalified,
requiring the testing of the WPS with these materials. Extreme caution should be used with copper
backing, as the arc may strike the copper and melt copper into the weld, greatly increasing the risk of
weld cracking.
C
(2) Welding personnel qualified to weld using backing are also qualified to weld without backing,
provided the weld is backgouged and backwelded. If the joint is not backgouged and backwelded, then
the welder must be qualified to weld without backing. If a welder is qualified without backing, then the
welder may also weld with backing.
(3) The minimum backing thicknesses provided in AWS D1.1 Section 5.10.3 are generally suitable
to reduce the risk of melting thru the backing bar, but very high heat input procedures, particularly with
Submerged Arc Welding (SAW), may require thicker backing.
(4) AWS D1.1 Section 5.10, includes provisions for backing materials, thickness, splicing, and
removal.
j. Weld Tabs. Weld tabs are also referred to as “extension bars”, “run-off tabs”, and similar terms in
the industry. The purpose of a weld tab is to allow the weld to be started or stopped beyond the edge of
the material being joined. Weld tabs are typically used in butt joint member splices, groove welded
5-7
CEMP-E
TI 809-26
1 March 2000
direct-welded flange joints in beam-to-column moment connections, and at the ends of built-up member
welds such as girder web-to-flange welds. Weld tabs allow the welding of the full width of the joint,
without starts and stops or build-out regions along the edges. The use of weld tabs places the inherent
weld discontinuities made when starting or stopping a weld within the tab, and outside the major stress
flow of the spliced material. Tabs also allow the welding arc to stabilize prior to welding the main
material. For SAW, the tabs support the flux deposit at the edge of the workpiece.
tabs.
EL
L
ED
(1) After welding is completed, the weld tabs may need to be removed. In some joints, particularly
in fatigue and high-seismic applications, it may be recommended or necessary to remove the weld tab
after use. Removal is required in most fatigue applications. In heavy section tensile splices, removal is
required. In high seismic regions, removal is required at transverse groove welds in moment-resisting
joints. For other applications, removal should be considered when splicing members over 25 mm (1 in.)
in thickness when the members are subjected to high tensile stresses at the splice. This is because
thicker members typically have less toughness than thinner members, and the low toughness may allow
a crack or other discontinuity in the weld tab to propagate into the primary weld. For compression joints
such as column splices, or for low-stress tensile splices, weld tabs in statically loaded structures should
be allowed to remain in place.
(2) AWS D1.1 Section 5.31, provides information on the use and removal requirements for weld
C
k. Welding Sequence and Distortion Control. Parts can be preset in a skewed position so that, when
weld shrinkage occurs, the completed member will be approximately straight. WPSs that use large
passes, rather than numerous small passes, generally cause less angular distortion. Distortion may also
occur along the length of a member, resulting in unintended sweep, camber, or twist. This occurs
because welding is not balanced about the center of gravity of the member cross-section. The use of
intermittent welding, welding from the center of the member’s length, and overwelding in some locations
may also be used to reduce longitudinal distortion.
AN
l. Lamellar Tearing. Lamellar tearing is a step-like crack in the base metal, generally parallel to the
rolled surface, caused by weld shrinkage stresses applied to the steel in the through-thickness direction.
The steel is somewhat weakened by the presence of very small, dispersed, planar-shaped, nonmetallic
inclusions, generally sulfur-based, oriented parallel to the steel surface. These inclusions serve as
initiation points for tearing. Large inclusions constitute laminations, which may be detectable using
straight-beam ultrasonic testing prior to welding. The inclusions that initiate lamellar tearing are generally
not reliably detected using any form of NDT.
C
(1) There is no specific through-thickness at which lamellar tearing will or will not occur, nor
specific values for weld size, stresses or strains that will induce tearing. Generally, lamellar tearing is
avoided by using one or more of the following techniques: improved design or redesign of the joint,
welding procedure controls, weld bead placement selection, sequencing, the use of preheat and/or
postheat, the use of low-strength, high-ductility filler metals, “buttering,” and peening. AWS D1.1
Commentary C2.1.3, provides guidance on these methods. Steels with improved through-thickness
properties may also be specified. The most common method for improving through-thickness properties,
to reduce the risk of lamellar tearing, is the specification of low-sulfur or controlled sulfur-inclusion steels.
(2) Should lamellar tears be detected, the stress type, application, and the implications of potential
failure in service should be considered. Because the completed joint is more highly restrained than the
original joint, repair of joints that have torn is difficult and expensive, with no assurance that a tear will
not form beneath the repair weld. Repair may involve complete removal of the existing weld and
5-8
CEMP-E
TI 809-26
1 March 2000
affected base metal. Reinforcement, if appropriate for the application, should be considered in lieu of
repair or replacement.
EL
L
ED
m. Brittle Fracture. Brittle fracture is a failure that occurs in the steel or weld without appreciable
deformation or energy absorption. Not all fractures are brittle, as the material may have undergone
considerable straining and deformation prior to fracture. Sufficient ductility should be provided in joint
design and detailing, and toughness in materials selection, so that brittle fracture will not occur. Many
joint designs assume the ability to deform and redistribute stress throughout the connection. Standard
design and detailing practices are typically adequate for building structures. Extreme loading conditions,
cold temperature environments, high seismic risk, unusual materials, and fatigue applications may
require more care in the selection and construction of connections and their details. Notches, whether
inadvertent or inherent in the design, greatly increase the risk of brittle fracture. Care should be taken to
avoid transversely loaded sharp notches and joint transitions, particularly in areas such as weld toes.
Backing bars should be removed in some applications because the notch inherent at the root pass
between backing bar and steel may initiate a crack in the weld, HAZ or base metal. Where it is assumed
that plastic behavior will be required to provide ductility and energy absorption, such as seismicallyloaded structures, sufficient length of base material should be provided in the assumed area of plastic
yielding to allow this to occur, and notches that would serve as crack initiators should be avoided in this
area. Notch-tough materials reduce the risk of brittle fracture.
4. DESIGN FOR CYCLICALLY LOADED STRUCTURES (FATIGUE).
C
a. General. The fatigue strength of a welded component is a combination of a stress range and a
number of cycles (N) that causes failure of the component. The stress range is the total range between
the maximum and minimum applied stresses. Stress range does not require stress reversal, only a
variation in stress. The fatigue life of a component, also called the endurance limit, is the number of
cycles to failure. The fatigue life of a welded joint is affected by the stress range at the location of crack
initiation, and the fatigue strength of the detail, primarily a function of its geometry. In welded joints,
fatigue life is generally not affected by applied stress level or the strength of the material.
AN
(1) Traditional fatigue design is based upon high-cycle fatigue, generally in the range of 20,000
cycles to 100,000 cycles and up. However, low-cycle fatigue may also occur in cases of extreme stress
and strain, such as seismic events or unanticipated out-of-plane bending from applied stresses or
distortion. Applications that may experience low-cycle fatigue require design and detailing specific to the
application that exceed the general fatigue design provisions of the codes.
C
(2) The S-N curves used for fatigue design provides an assumed relationship between fatigue life
and stress range, and are commonly plotted on a logarithmic scale as a straight line. At the upper left
end of the straight line, at the low endurance limit, the ultimate material strength is exceeded and failure
occurs from static stress. At the lower right end of the curve, the high-endurance range, the stress ranges
are generally too low to initiate crack propagation. The design S-N curves used to design structural
members have been established approximately 25% below the mean failure values. Several design
codes are now replacing the design S-N curves with the equations used to generate the plotted curves.
(3) The fatigue strength of different welded details varies according to the severity of the stress
concentration effect. Those with similar fatigue life characteristics are grouped together into a Stress
Category, identified as Classes A through F, with subcategories for special cases. There are several
details that fall within each class. Each detail has a specific description that defines the geometry. The
details and stress categories are classified by:
5-9
CEMP-E
•
•
•
•
•
TI 809-26
1 March 2000
form of the member (plate base metal, rolled section base metal, weld type),
location of anticipated crack initiation (base metal, weld, weld toe),
governing dimensions (attachment dimensions, radius of transition, weld length, etc.),
fabrication requirements (ground flush, backing removed, etc.), and
inspection requirements (ultrasonic or radiographic testing). The detail category should be
evaluated carefully to verify that the actual detail realistically matches the standard detail.
•
•
•
•
•
•
•
AN
•
EL
L
•
•
Grinding groove welds flush in the direction of the applied stress may improve the Stress
Category.
Avoid reentrant, notch-like corners.
Transitions between members of differing thicknesses or widths should be made with a
slope of at least 2.5:1.
Joints should be placed in low stress areas, when possible.
Groove-welded butt joints have better fatigue life than lap or tee joints made with fillet
welds.
Parts should be aligned to minimize or eliminate eccentricity and minimize secondary
bending stresses.
Avoid attachments to members subject to fatigue loading.
Attachment welds should be kept at least 12 mm (1/2 in.) from the edges of plates.
Welds on the edges of flanges should be avoided. Fillet welds should be stopped about 12
mm (1/2 in.) short of the end of the attachment, provided this will not have any other
detrimental effect on the structure.
If a detail is highly sensitive to weld discontinuities, such as a transversely loaded CJP
groove weld with reinforcement removed, appropriate quality, inspection, and NDT
requirements should be specified.
Fatigue life enhancement techniques such as those found in AWS D1.1 Section 8, may be
cost-effective in extending fatigue life.
When grinding is appropriate, grinding should be in the direction of stress.
Intermittent stitch welds should be avoided. Unauthorized attachments, often made by field
or maintenance personnel or other trades, must be prohibited.
A bolted assembly may be appropriate and more cost-effective in some applications.
For critical details, provide for in-service inspection.
C
•
ED
(4) Careful design and fabrication can reduce the risk of failure by fatigue. Not all methods of
fatigue life improvement are contained in the Codes, and not all methods are necessary. Smooth shapes
and transitions are important, but radiused transitions are expensive and may not substantially improve
fatigue life.
•
•
•
•
C
b. Fatigue Design Details. Fatigue details are identified as plain material, built-up members, groove
welds, groove-welded attachments, fillet welds, fillet-welded attachments, stud welds, and plug and slot
welds. Further divisions of these general categories are provided using general descriptions, and in some
cases, by attachment length, radius, grinding requirements, NDT requirements, and member yield
strength. Illustrative examples are typically provided by the codes to assist in the interpretation of these
divisions.
(1) Stress Category A is limited to plain material, with no welding. Categories B, C, D and E follow
the same line slope, with reduced permitted stress ranges for a given fatigue life demand. Category F
behavior is sufficiently different to use a different slope. The endurance limit is also reached soonest, at
the highest stress range, for Category A details, with progressively more cycles and lower stress ranges
for the endurance limit in other categories.
5-10
CEMP-E
TI 809-26
1 March 2000
(2) Various design codes may be used for fatigue design, and all are based upon the same
principles and research data. Occasional revisions to these provisions and details are made by the
various code organizations, so there may be minor differences between codes. Generally, AISC and
AASHTO specifications are the most current and comprehensive, including bolted details. AWS D1.1
provisions are limited to welded details. AASHTO and AWS currently use S-N curves, and AISC uses
tabular values based upon the S-N curves. All three organizations are currently changing to equationbased design.
ED
(3) AASHTO and AWS provide fatigue design curves for both redundant and nonredundant
structures. The AWS nonredundant structure fatigue provisions are based upon bridge principles, where
failure of the welded component would result in collapse of the structure, but special provisions for
nonredundant structures are not required. The AASHTO code, however, requires the use of the AWS
D1.5, Section 12, Fracture Control Plan for Nonredundant Structures. As a specification for building
construction, AISC does not address nonredundant applications.
EL
L
c. Allowable Stress Ranges. Stress ranges at the lower number of cycles, for the better fatigue
categories, are often limited by the static stress applied. Because the number of cycles is usually
established for the application, and often the type of detail needed to make the component or connection
is established, the design must be established to keep the stress range below that permitted. Fatigue
design begins with the sizing of the member and the connection for the maximum applied static load,
then checked for the applied stress range. Adjustments are then made to increase the component or
connection size as needed. Should the size become excessive, other improved details may be
considered. This includes, for some groove details, grinding of the surface and NDT to improve the
fatigue design category. Some joints may be changed from PJP groove or fillet welds to CJP groove
welds. Another alternative is the use of fatigue life enhancement details to improve fatigue life. Fatigue
life enhancement details are not to be used to increase allowable stress ranges.
C
AN
C
d. Fatigue Life Enhancement. At the toe of every weld, with the exception of welds made using
Tungsten Inert Gas (TIG) welding with no filler metal, a microscopic slag intrusion line is present. This
line, for fatigue purposes, acts as a small crack. Fatigue life of welded joints, therefore, begins with an
initial crack, and fatigue life is limited to crack propagation. With plain material, there is no pre-existing
crack, so fatigue life is spent in both crack initiation and crack propagation. By applying fatigue life
enhancement techniques, as described in AWS D1.1 Section 8, fatigue life may be extended. The
process of TIG dressing can be used to remelt the weld toe area to a limited depth, melting out and
removing the microscopic slag intrusion line. Burr grinding of the weld toe, to a depth of approximately 1
mm (1/32 in.), may also be used to remove the slag line. Toe peening, in which localized mechanical
compressive stresses are induced into the weld toe area, does not remove the slag line, but induces
residual compressive stresses around the slag line to prevent the introduction of the tensile stresses
necessary for crack propagation. Any of these enhancement processes typically double the fatigue life of
the treated joint. Performing both toe grinding and hammer peening will provide additional benefits,
achieving typically triple the fatigue life of the untreated weld toe. Caution should be used when
extending fatigue life expectations, as other areas of the welded joint may now fail before the weld toe.
Inspection of the weld should be performed prior to implementing fatigue life enhancement techniques,
with any required inspection for surface discontinuities repeated following the work.
5. HIGH SEISMIC APPLICATIONS.
a. Latest Guidance. Recommendations for the design of welded connections in high seismic regions
are undergoing substantial revision as of the date of this document. Users are advised to seek the latest
5-11
CEMP-E
TI 809-26
1 March 2000
guidance from FEMA and AISC documents.
ED
b. Applicability. Improved materials and details should be used for building structures classified as
Seismic Categories D, E and F. These applications include all buildings located in areas with 1 second
spectral response accelerations (S D1) of 0.20g or higher, or short period response accelerations (S DS) of
0.50g, and buildings of Seismic Use Group III in areas with S D1 of 0.133g or higher, or S DS of 0.33g or
higher. Seismic Use Group III structures are essential facilities that are required for post-earthquake
recovery and those containing substantial quantities of hazardous substances, including but not limited
to: fire, rescue and police stations; hospitals; designated medical facilities providing emergency medical
treatment; emergency operations centers; emergency shelters; emergency vehicle garages; designated
communications towers; air traffic control towers; and water treatment facilities needed to provide water
pressure for fire suppression. See TI 809-04, Table 4-1 for Seismic Use Groups, and Section 4.2 for
Seismic Design Categories.
EL
L
c. Materials Concerns and Specifications. Special compositional, materials toughness and other
mechanical property requirements may be necessary for the steel and filer metal used in seismic
applications:
(1) The AISC Seismic Provisions, Section 6.3, require steel in the Seismic Force Resisting System
to have a minimum toughness of 27J at 21 oC (20 ft.-lbf at 70oF), applicable to ASTM Group 4 and 5
shapes, Group 3 shapes with flanges 38 mm (1-1/2 in.) or thicker, and to plates in built-up members 38
mm (1-1/2 in.) or thicker.
C
(2) Studies indicate that a large percentage of domestically produced structural steel sections
lighter or thinner than those mentioned in the previous paragraph will have a CVN toughness of at least
27J at 21oC (20 ft.-lbf at 70oF), and therefore it does not appear that CVN testing need be conducted to
verify the toughness of all members. It is recommended that manufacturer’s accumulated data be used
to verify that the steel routinely produced by that mill meets the indicated toughness levels. Specification
of steel toughness levels, or the specification of A709 steels, is currently considered unnecessary for
building-type applications.
AN
(3) It is also recommended that structural steel shapes used in high seismic applications be
specified as either ASTM A992 or A572, grade 50 manufactured to AISC Technical Bulletin #3. These
specifications have provisions for a maximum ratio of F y to Fu of 0.85, and a more controlled chemistry
for weldability and properties.
C
(4) The AISC Seismic Provisions, section 7.3b, require filler metals in the Seismic Force Resisting
System to have a minimum toughness of 27J at -29 oC (20 ft.-lbf at -20oF). Additional requirements for
toughness at service temperature, tested using welding procedures representative of the range of
production WPSs, are also recommended in the latest FEMA Guidelines.
(5) There are concerns for the performance of rolled steel sections in the vicinity of the K-line, at
the intersection of the web and the radius between web and flange. Studies have identified a reduced
toughness in this region caused by cold-working during rotary straightening at the steel mill. Reduced
toughness in these region may increase the risk of crack initiation from welding in the area, particularly
stiffeners (continuity plates) and doubler plates. AISC Technical Advisory No. 1 should be followed,
pending further study.
(6) Current studies indicate that through-thickness toughness properties or applied stress on the
column face is not a limiting factor, and need not be specified or checked.
5-12
CEMP-E
TI 809-26
1 March 2000
d. Joint Selection. Several types of details may be used to achieve satisfactory moment connection
performance in high seismic applications. Enhanced quality, improved and reinforced details are
recommended for conventional-type connections. See (e) below. For Reduced Beam Section (RBS)
system connections, also called the “dogbone” system, current AISC guidelines should be followed. See
Appendix D, Bibliography. Several limitations have been found in the cover-plated and ribbed details,
and further investigation of the latest recommendations should be made prior to use.
ED
e. Joint Detail Modifications and Enhancements. Current recommendations include the following
modifications to the previous standard beam-to-column connection: (1) removal of bottom flange backing
bar, backgouging of the root, and placement of a reinforcing fillet, (2) improved quality of the weld
access hole, (3) removal and finishing of weld tabs, (4) control of profile and quality of the access hole,
(5) use of partially or fully welded web connections. The exact requirements for access hole provisions
and web welding depend upon the type of connection used and the design application, whether Special
Moment resisting Frame (SMRF) or Ordinary Moment-Resisting Frame (OMRF).
C
AN
C
EL
L
f. Inspection Enhancements. Continuous inspection of all welding performed on CJP and PJP groove
welds that are a part of the Seismic Force Resisting System is necessary. The Engineer may allow
periodic inspections when appropriate. AISC Seismic Provisions require NDT for certain joints in high
seismic applications, as follows: “All complete joint penetration and partial joint penetration groove
welded joints that are subjected to net tensile forces as part of the Seismic Force Resisting Systems ...
shall be tested using approved nondestructive testing methods conforming to AWS D1.1.” Such testing
should include ultrasonic testing of welds in T-joints and butt joints over 8 mm (5/16 in.) in thickness.
Radiographic testing may be used in some cases using butt joints. When using T-joints, with the
thickness of the tee “flange” exceeding 40 mm (1-1/2 in.), ultrasonic testing should be performed after
completion and cooling of the weld to check for lamellar tearing.
5-13
CEMP-E
TI 809-26
1 March 2000
CHAPTER 6
STUD WELDING
1. GENERAL.
EL
L
2. STUD WELDING PROCESS.
ED
Stud welding for building applications is generally for shear connectors in composite beams, but may
also include shear connector applications for composite columns and frames. Studs may be welded
either directly to the structural steel or through metal decking. The purpose of most shear connectors is
to integrally connect steel and concrete materials so that they act as a single unit in resisting load.
Occasionally, threaded studs may be used for special connections where bolting is not practical, such as
embedment plates or inaccessible connections. Stud welding is a fully automated process with controlled
arc length and arc time, and is conducive to a suitable convenient load test, and therefore is treated
separately by AWS D1.1 for procedure qualification, personnel qualification, and inspection.
C
The arc stud welding process is used for structural studs, rather than the capacitor discharge stud
welding process. A DCEN (straight) current is used to create an arc between the stud base and the steel.
The stud welding gun draws the stud away from the steel, creating the arc, allows a brief period for the
melting of the steel and stud base, then plunges the stud into the molten pool and terminates the current
flow. The weld arc and molten pool is protected with the use of a flux tip on the base of the stud, plus the
use of a ceramic ferrule to contain the molten pool. See AWS C5.4, Recommended Practice for Stud
Welding, for complete information.
3. STUD BASE QUALIFICATION.
AN
Stud bases are qualified by the manufacturer for application on bare steel in the flat position only.
Qualification procedures for this application are provided in AWS D1.1 Annex IX. For all other
applications, including studs applied through metal decking, studs applied to curved surfaces, studs
welded in vertical or overhead positions, or studs welded to steels not listed as Group I or II in AWS D1.1
Table 3.1, the contractor must perform qualification testing. For the Type B studs used in composite
construction, ten (10) specimens must pass a 90 o bend test using representative material and
application. Alternatively, a tension test method may be used. See AWS D1.1 Section 7.6.
C
4. WELDING PERSONNEL QUALIFICATION.
The welding operator conducting the two pre-production tests at the start of the day or work shift is
qualified for performing stud welding that day or shift. See AWS D1.1 Section 7.7.4.
5. PRE-PRODUCTION TESTING.
After stud base qualification by the manufacturer, or qualification testing by the contractor for the
applications listed, installation may begin. However, pre-production testing is required at the start of each
day or shift to verify the setup of the equipment. This testing requires two studs to be welded, on the
6-1
CEMP-E
TI 809-26
1 March 2000
work if desired, visually inspected, then bent approximately 30 o. If the stud weld passes the visual and
bend testing, then production welding may begin. For composite construction, the stud need not be bent
back to the original position. See AWS D1.1 Section 7.7.1. The pre-production test must be repeated
whenever there are changes to the following items: voltage, current, time, or gun lift and plunge.
6. INSPECTION.
C
AN
C
EL
L
ED
Following the application of studs and the removal of the ferrules, all stud welds are visually inspected
for flash about the entire perimeter of the stud base. Those with missing flash may be repaired, or tested
using a bend test applied approximately 15 o in the direction opposite the missing flash. Should the stud
weld not fracture, the stud is accepted and may be left in place in the bent condition when used in
composite construction. The inspector may 15 o bend test any stud, if desired, even if full flash is
apparent. See AWS D1.1 Section 7.8.
6-2
CEMP-E
TI 809-26
1 March 2000
CHAPTER 7
WELDING TO EXISTING STRUCTURES
1. GENERAL.
ED
When welding to reinforce existing structures, several areas require investigation and, in some cases,
specific instructions. Other than load analysis of the structure to design the connections, several welding
issues arise. These include weldability of the existing steel, the reduction of strength to existing members
when being heated or welded, and the welding to existing weld deposits of unknown origin or made with
FCAW-S electrodes. AWS D1.1 Section 8, and its supporting Commentary, provides applicable code
provisions.
2. DETERMINING WELDABILITY OF EXISTING STRUCTURAL STEELS.
b. Carbon Equivalency.
EL
L
a. Investigation. Investigation of weldability is generally warranted for buildings constructed prior to
1945, although structural steels were not manufactured specifically for welding properties until A373 and
A36 came into use in the early 1960’s. The weldability of steels between these periods is generally
considered sufficiently weldable.
C
(1) The most reliable method to establish chemical composition for determining carbon equivalent
values is to remove samples from various members at selected no- or low-stress locations, then
analyzed spectrographically for composition. Portable spectrographs may also be used, although only
optical emission spectrography systems currently provide sufficient accuracy for measuring carbon
content. The laboratory analysis report should list the quantities of each of the elements in the selected
carbon equivalent equation, even if the percentage reported is zero.
AN
(2) Other methods, although less reliable, include spark testing and weld sample tests. Spark
testing applies a grinding wheel at approximately 5000 rpm to the steel, then observing and
characterizing the color and nature of the sparks off the steel. Weld sample tests include welding small
test plates to the steel, then destructively using a sledge hammer to break off the samples, if possible,
and observing the nature of the fracture.
C
3. WELDING TO OLDER STRUCTURAL STEELS.
The poorer the weldability of steel, the greater the need for higher preheat and interpass temperatures,
and the greater the importance of low-hydrogen welding. All welding to existing structures should be
performed with low-hydrogen SMAW electrodes or with other wire-fed welding processes. Minimum
preheat and interpass temperatures can be determined from AWS D1.1 Annex XI, or from technical
literature.
4. INTERMIXING WELD PROCESSES AND FILLER METALS.
a. FCAW-S Deposits. Self-shielded Flux-Cored Arc Welding (FCAW-S) weld deposits contain
7-1
CEMP-E
TI 809-26
1 March 2000
aluminum, nitrogen, carbon and other alloying elements. When weld processes that use consumables
with significantly different metallurgical systems are mixed with FCAW-S deposits, there is the potential
for reduced properties, particularly ductility and toughness. This is the result of the liberation of nitrogen
and aluminum that were previously chemically combined as Al-N in the FCAW-S deposit. Other weld
deposits, typically a carbon-manganese-silicon metallurgical system, do not contain the amount of
aluminum necessary in order to preclude the formation of free nitrogen, which can embrittle the steel or
weld deposit.
ED
b. Investigation. When it is suspected that existing weld deposits that will receive subsequent welding
were made using FCAW-S, further investigation of the weld deposit is warranted. An aluminum content
in the range of 1% is indicative of FCAW-S. Low-admixture welding procedures, design assuming
reduced mechanical properties, or requiring subsequent welding using appropriate FCAW-S should be
considered.
EL
L
c. Other Processes. Recent research indicates that this problem may not be limited to non-FCAW-S
weld deposits on top of FCAW-S. Multiple weld processes in a single weld joint may also occur in new
construction because of tack welding, root pass welding selection, or other reasons.
5. STRENGTH REDUCTION EFFECTS AND OTHER CONCERNS WHEN WELDING UNDER LOAD.
C
a. Elevated Temperature Effects. Elevated temperatures in steel reduce both the yield strength (F y)
and the modulus of elasticity (E). At approximately 300 oC to 400oC (600oF to 800oF), Fy and E are
reduced approximately 20%. Preheat temperatures at this level are rarely used, but localized
temperatures near the weld region will exceed these temperatures for brief periods. As a general guide,
steel during welding, within the weld region, will exceed these temperatures approximately 25 mm (1 in.)
to the side of a weld, and a distance of approximately 100 mm (4 in.) trailing the weld puddle. Steel
further from the weld region will remain at temperatures that will not significantly reduce the steel’s
properties.
AN
b. Welding Direction and Sequence. When welding under load, consideration should be made for the
temporarily reduced strength of localized areas of the steel. When welding parallel to the applied stress,
the affected area is typically small compared to the area of the unaffected steel. When welding
transverse to the load, additional caution is needed. It may be necessary to stagger welding operations,
use shorter sections of weld and then allow cooling, or use lower heat input procedures.
6. HAZARDOUS MATERIALS.
C
When welding on steel having existing coatings, an investigation into the composition of the coating is
warranted, unless all coatings in the vicinity of the welding are removed prior to welding. Zinc, used in
numerous coating systems and galvanizing, produces noxious fumes. Some older structures may contain
lead-based paints that must be removed using special hazardous materials precautions.
7-2
CEMP-E
TI 809-26
1 March 2000
CHAPTER 8
QUALITY ASSURANCE AND INSPECTION
1. GENERAL.
ED
The Engineer is responsible for establishing and specifying the requirements of the Quality Control and
Quality Assurance programs for the project. These requirements should be a part of the contract
documents. AWS D1.1 requires inspection of welding, but requires only “Fabrication / Erection
Inspection”, which is the designated responsibility of the Contractor. “Verification Inspection” is the
prerogative of the Owner, under AWS D1.1. Therefore, any specific welding inspection operations to be
performed by personnel other than the Contractor must be fully detailed and placed in the contract
documents.
EL
L
2. REVIEWING AND APPROVING WELDING PROCEDURES.
C
a. WPS Contents. Welding procedures are used to specify, for the welder and inspector, the welding
parameters for the weld to be made. Weld procedures are written by the contractor responsible for the
welding, and must be reviewed by the inspector. In some cases, the Engineer must approve the welding
procedures. Welding Procedure Specifications (WPSs) are written based upon the steel to be welded,
thickness of material to be joined, type of joint, type of weld, size of weld, and position of welding. Based
upon the application, the WPS specifies the welding materials to be used (electrode, flux, shielding gas),
electrode diameter, voltage, current (amperage) or wire feed speed, travel speed, shielding gas flow rate,
minimum (and sometimes maximum) preheat and interpass temperatures, location and number of
passes, and other pertinent information specific to the weld to be made. All WPSs, whether prequalified
or qualified by test, must be in writing.
AN
b. AWS Requirements. AWS D1.1 Section 6.3.1 requires the use of and inspection of WPSs. The
inspector should review the WPS for general conformity to the welding code and applicability to the joint
to be welded. The WPS also provides information necessary for inspection duties. The Engineer is
assigned the responsibility in AWS D1.1 Section 4.1.1, to review and approve WPSs that are qualified.
Prequalified WPSs need not be approved by the Engineer under D1.1. The purpose of the Engineer’s
approval of the WPS is so that it can be verified that the qualification testing is representative of the
actual welding conditions, such as for thick and highly restrained joints.
C
c. AISC Requirements. In the AISC Seismic Provisions, Section 7.3, the Engineer is made
responsible for the review and approval of all WPSs, whether qualified or prequalified, for welds that are
part of the Seismic Force Resisting System. This is primarily to ensure that WPSs are developed for the
welds critical to building performance, and that filler metals with the required toughness have been
selected by the contractor.
d. WPS Prequalification Limits. Prequalified WPSs need not be tested using the tests prescribed in
AWS D1.1 Section 4. The contractor may develop WPSs based upon manufacturer’s recommended
operating parameters, verified by the contractor’s experience and testing as desired. To be prequalified,
the welding process must be prequalified (SMAW, FCAW, GMAW except short-circuiting transfer, or
SAW), the weld details must meet all the requirements of AWS D1.1 Section 3, and welding parameters
meet the provisions of AWS Table 3.7. This includes the use of the prequalified groove weld details in
AWS Figures 3.3 and 3.4, minimum prequalified PJP groove weld size in AWS Table 3.4, and minimum
8-1
CEMP-E
TI 809-26
1 March 2000
fillet weld size in AWS Table 5.8. “Matching” filler metals must be used, per AWS Table 3.1, and
minimum preheat and interpass temperatures must be provided per AWS Table 3.2.
ED
e. WPS Qualification Requirements. When WPSs, joints, filler metal selection, or other details do not
meet the prequalification requirements of AWS D1.1 Section 3, the WPS to be used for the joint must be
qualified by testing prescribed in AWS D1.1 Section 4. Documentation of the WPS used and test results
must be documented in the form of Procedure Qualification Records (PQRs). Qualified WPSs must be
referenced to the applicable PQR. PQRs must be in writing, and made available for inspection by the
inspector.
f. Guidance for Engineering Review of Procedures Submitted by Contractors. For review of WPSs,
the contractor should submit all applicable manufacturer data sheets and operating recommendations for
the filler material to be used. It may also be necessary to consult the AWS A5.XX filler metal
specifications for information regarding the use and limitations of the filler metal.
EL
L
(1) Generally, manufacturer’s operating recommendations provide a range of welding parameters
such as voltage and current (amperage) or wire feed speed, and specify polarity, but do not provide
specific travel speeds or adjustments necessary to achieve a particular weld size. The middle of the
provided ranges are often good starting points, but contractors often tend to work near the high end of
the ranges provided to maximize deposition rates and reduce welding time.
(2) Calculations such as heat input and deposition rates are helpful in determining if WPSs should
produce a reasonable quality weld of the size specified. However, it is often difficult to verify FCAW
procedures through calculation because of the variations between specific electrode types. Calculation
should not be used to determine optimum operating characteristics for welding, as these final
adjustments are made by experience. See references in Appendix B.
AN
C
(3) Caution should be used when reviewing WPSs for thick materials and highly restrained joints.
The 25 mm (1 in.) test plate thicknesses specified in AWS D1.1 Section 4, do not adequately represent
the heat sink capabilities of thicker sections (affecting cooling rates), nor is restraint developed in the
welding of standard WPS test specimens. The use of thicker plates and NDT, and the use of restraint
devices, should be specified as appropriate for critical welding. Alternately, other WPS testing methods
may be used as appropriate.
(4) A checklist should be prepared to verify that all welded joints on the project have written WPSs.
Critical joints should be reviewed to verify that the proper welding materials have been designated for the
joint, particularly when CVN toughness is required.
C
(5) Approval of the WPS should be taken as review only, and that the responsibility for the
suitability of the WPS, and the resultant weld quality and properties, remains with the contractor.
3. WELDING PERSONNEL QUALIFICATION.
a. Personnel Classification. Welding personnel are classified into three categories: welders, welding
operators, and tack welders. Welders manipulate the electrode by hand, manipulating and controlling the
arc, for manual or semi-automatic welding. Welding operators set up automatic welding equipment with
wire-fed welding processes, such as mechanized SAW, to travel at selected speeds. Tack welders may
only place tack welds to assemble pieces, with the finish welds to be performed by qualified welders or
welding operators.
8-2
CEMP-E
TI 809-26
1 March 2000
ED
b. Qualification Testing. All welding personnel must demonstrate their skill by performing specific
performance qualification tests prescribed by AWS D1.1 Section 4, Part C. Welders are qualified by
process - SMAW, FCAW, GMAW, SAW, GTAW, ESW, or EGW. FCAW-S (self-shielded) and FCAW-G
(gas-shielded) are considered the same process for performance qualification testing. Welders are also
qualified by position - Flat, Horizontal, Vertical and Overhead. These are designated on welding
personnel qualification records as positions 1, 2, 3, and 4, respectively. Welding personnel qualified for
more difficult positions, for example Vertical (3), are also qualified for Flat (1) and Horizontal (2) welding.
However, Vertical (3) and Overhead (4) welding positions are considered separately. Additional position
classifications apply for tubular construction, and are further identified in AWS D1.1 Figures 4.4 and 4.6.
Welding personnel are further classified by type of weld, testing using groove welds or fillet welds.
Welding personnel qualified for groove welding in a given position and process are also qualified for fillet
welding in the same position and process. Those who qualify using 9.5 mm (3/8 in.) thick plate or thicker
are qualified for twice the test plate thickness. Welding personnel qualified using 25.4 mm (1 in.) thick
plate are qualified for unlimited thicknesses of material. AWS D1.1 Table 4.8 provides complete
information regarding the cross-over of welding performance qualifications tests and the welding
products, thicknesses and positions qualified.
EL
L
c. Contractor Responsibilities. The contractor is responsible for the qualification of all welding
personnel. The witnessing of performance testing is not required. All performance qualification tests must
be fully documented in writing. Performance qualification expires six (6) months following testing, unless
the person has used the process during that time period. Should a person not use the process within six
months, the qualification period expires. There should be records documenting the use of various
processes by the contractor. Welding position is not a factor in maintaining welding personnel
qualification. Should the welder consistently produce poor quality welds, the welder’s qualification can be
revoked, requiring retesting.
AN
C
d. Qualification Testing by Others. Although standard practice is to require contractor-based
qualification testing of welding personnel, it is acceptable, with the Engineer’s approval, for the contractor
to rely upon qualification testing performed by others. Such testing may include independent testing
laboratories, welding vocational schools, industry associations and unions, and the AWS Certified
Welder program. The Engineer should review the basis and suitability of such programs prior to waiver
of contractor-based qualification.
4. INSPECTOR QUALIFICATIONS
C
a. General Welding and Visual Inspectors. Visual welding inspection personnel should be qualified
under AWS D1.1 Section 6.1.4. The basis of qualification, if beyond these provisions, must be specified
in the project documents. Acceptable qualification bases under D1.1 are: (1) current or previous
certification as an AWS Certified Welding Inspector (CWI) in accordance with the provisions of AWS
QC1, Standard for AWS Certification of Welding Inspectors, or (2) current or previous qualification by the
Canadian Welding Bureau (CWB) to the requirements of the Canadian Standard Association (CSA)
Standard W178.2, Certification of Welding Inspectors, or (3) an engineer or technician who, by training or
experience, or both, in metals fabrication, inspection and testing, is competent to perform inspection
work. For the third case, the Engineer should establish minimum levels of training and experience,
require a written resume detailing training and experience in welding inspection, and require a written
and hands-on examination prior to approval of the inspector.
(1) The qualification of an previously certified inspector remains in effect indefinitely, even though
the certification may have expired, provided the inspector remains active in the inspection of welded
8-3
CEMP-E
TI 809-26
1 March 2000
steel fabrication, or unless there is a specific reason to question the inspector's ability.
ED
(2) The American Welding Society offers certification to welding inspectors in the form of Certified
Welding Inspectors, Certified Associate Welding Inspectors, and Certified Senior Welding Inspectors.
ANSI/AWS QC1-96, Standard for AWS Certification of Welding Inspectors, governs the requirements
and testing of such inspectors, including experience level. The CWI examination tests the inspector’s
knowledge of welding processes, welding procedures, welder qualification, destructive testing,
nondestructive testing, terms, definitions, symbols, reports, records, safety and responsibilities. Although
assumed to be competent to inspect welded construction, the AWS Certified Welding Inspector may not
have the background or expertise in other areas of steel construction such as general fabrication and
erection, bolted connections, steel bar joists, and metal decks, and additional education and training
relative to these areas may be needed. It should also be verified that the AWS Certified Welding
Inspector has tested, or is familiar with, the AWS D1.1 Structural Welding Code. It is permitted to take
the AWS examinations using either the AWS D1.1, ASME Boiler and Pressure Vessel Code, or the API
1104 Welding of Pipelines and Related Facilities code, and welding inspection experience may be in any
area of welding.
EL
L
(3) AWS D1.1 does not recognize the AWS Certified Associate Welding Inspector as qualified to
perform the work solely based upon this certification. A CAWI has passed the same accreditation
examination as the CWI, but has less experience, with two years minimum experience rather than five
years, in the field of welding inspection. A CAWI could be acceptable under condition “c” as listed in
AWS D1.1 Section 6.1.4. The Senior Certified Welding Inspector is a new program offered by the AWS,
and this recent certification option has not been included in the AWS D1.1 code because of publication
schedules. A SCWI should be considered the equivalent of a CWI.
C
(4) Although AWS D1.1 allows inspector qualification without the CWI certification under AWS
QC1 criteria, it is recommended that the welding inspection personnel for critical welding be AWS QC1
certified (or previously certified) by experience and written examination.
AN
(5) All welding inspectors must have adequate visual acuity, documented by vision testing
performed within the past three years. See AWS D1.1 Section 6.1.4.4.
b. NDT Personnel Qualification. Certification of all levels of NDT personnel is the responsibility of the
employer of the NDT technician. Nondestructive testing personnel should be qualified under the
American Society for Nondestructive Testing, Inc., ANSI/ASNT CP-189, ASNT Standard for Qualification
and Certification of Nondestructive Testing Personnel, or ASNT Recommended Practice No. SNT-TC-1A,
Personnel Qualification and Certification in Nondestructive Testing.
C
(1) Certification of NDT personnel should be based on demonstration of satisfactory qualification in
accordance with Sections 6, 7 and 8 of ASNT SNT-TC-1A, as modified by the employer's written
practice, or in accordance with Sections 4, 5 and 6 of ANSI/ASNT CP-189. Employers may rely upon
outside training and testing for NDT personnel for certification, however, the employer should
supplement such certification testing with a review of the technician’s experience and skill levels. It is
suggested that the certification of NDT personnel should be administered by an ASNT Certified Level III
in the specific area on NDT. Personnel certifications must be maintained on file by the employer and a
copy should be carried by the technician.
(2) AWS D1.1 Section 6.14.6 requires that nondestructive testing be performed by NDT Level II
technicians, or by Level I technicians only when working under the direct supervision of a Level II.
Inspection by a Level III technician is not recognized, as the Level III may not perform actual testing
8-4
CEMP-E
TI 809-26
1 March 2000
regularly enough to maintain the special skills required to set up or to conduct the tests. AWS D1.5-96
requires similar qualification, except in the case of Fracture Critical Members. Under Section 12.16.1.2,
testing of Fracture Critical Members must be done by either a qualified Level II under the supervision of
a qualified Level III, or by a Level III certified by ASNT, unless the Engineer accepts other forms of
qualification.
EL
L
ED
(3) The following definitions, from ANSI / ASNT CP-189, apply to the various NDT Levels:
• NDT Level I - An NDT Level I individual shall have the skills to properly perform specific
calibrations, specific NDT, and with prior written approval of the NDT Level III, perform
specific interpretations and evaluations for acceptance or rejection and document the
results. The NDT Level I shall be able to follow approved nondestructive testing
procedures and shall receive the necessary guidance or supervision from a certified NDT
Level II or NDT Level III individual.
• NDT Level II - An NDT Level II individual shall have the skills and knowledge to set up and
calibrate equipment, to conduct tests, and to interpret, evaluate, and document results in
accordance with procedures approved by an NDT Level III. The Level II shall be
thoroughly familiar with the scope and limitations of the method to which certified and
should be capable of directing the work of trainees and NDT Level I personnel. The NDT
Level II shall be able to organize and report nondestructive test results.
• NDT Level III - An NDT Level III individual shall have the skills and knowledge to establish
techniques; to interpret codes, standards, and specifications; designate the particular
technique to be used; and verify the accuracy of procedures. The individual shall also
have general familiarity with the other NDT methods. The NDT Level III shall be capable
of conducting or directing the training and examining of NDT personnel in the methods for
which the NDT Level III is qualified.
C
5. INSPECTION CATEGORIES AND TASKS.
C
AN
a. General. The inspector assigned responsibility for the welding of the project should review and
understand the applicable portions of the project specifications, the contract design drawings, and the
shop or erection drawings for the project, as appropriate. The inspector should participate in a pre-project
meeting with the contractor to discuss the quality control and quality assurance requirements for the
project. A record should be kept of all welders, welding operators and tack welders, welding personnel
qualifications, welding procedures, accepted parts, the status of all joints not accepted, NDT test reports,
and other such information as may be required. The inspector’s duties can be assigned or placed into
four general categories, by time period: pre-project inspection for general welding operations, inspection
prior to welding a particular joint, inspection during welding of the joint, and inspection of the completed
joint.
b. Pre-project Inspection. A pre-project inspection should be conducted of the fabricator’s and
erector’s facilities and operations to verify the adequacy of their welding operations. The scheduling of
this inspection should be well before welding is scheduled to begin, allowing time for necessary
corrections and improvements by the contractor before welding begins.
(1) Personnel. The inspector should verify that all applicable welder, welding operator and tack
welder qualification records are available, current and complete, and that any required special
supplemental qualification tests, such as mock-ups, have been passed. Requalification is required for
any welder, welding operator or tack welder who has, for a period of six months, not used the process for
which the person was qualified. Each person performing welding should have a unique identification
8-5
CEMP-E
TI 809-26
1 March 2000
mark or die stamp to identify his or her welds. See AWS D1.1 Section 4, Part C.
ED
(2) Equipment. All welding equipment should be in proper operating condition, with functioning
gauges necessary for following the WPS for the selected process. Periodic checks should be performed
by the contractor to verify the accuracy of gauges and other operating components of welding machines.
Welding leads should be inspected for worn or missing insulation, or inadequate connectors. Ammeters
should be available for verifying the current (amperage) near the arc, rather than at the machine.
Records of equipment inspections and calibrations should be maintained, but there is no specific
requirements for such in AWS D1.1. Inspections at least annually are recommended. See AWS D1.1
Sections 5.11 and 6.3.2.
EL
L
(3) WPSs. The inspector should verify that all applicable welding Procedure Qualification Records
(PQRs) and Welding Procedure Specifications (WPSs) are available, current and accurate. WPSs
should be available at welding work stations and used by all welding personnel. PQRs should be
referenced and available for review for any non-prequalified WPSs. Qualified WPSs must be approved
by the Engineer, per AWS D1.1 Section 4.1.1. For high seismic applications, all WPSs must be
approved by the Engineer. See AISC Seismic Provisions Section 7.3a. The Engineer’s approval should
be verified.
(4) Materials Controls. Electrodes and fluxes should be stored in their original, manufacturersealed containers until ready for placement in storage ovens or use. The manufacturer’s identification
labels, including lot number, should remain on the packaging. The contractor should have an operating
system to verify that all materials in inventory have proper certification papers on file. The contractor’s
quality control system should be used to confirm that the proper welding consumables are selected.
AN
C
(5) Materials Storage. The contractor should have all necessary welding consumable drying and
storage equipment. The proper operating temperatures should be verified on a regular basis as a part of
the contractor’s quality control program. Welding personnel should be familiar with the SMAW electrode
and SAW flux storage and exposure limitations of AWS D1.1, with an ongoing system in place to confirm
compliance. No materials other than electrodes or fluxes, as appropriate, may be placed in drying or
storage ovens. See AWS D1.1 Section 5.3 for storage requirements. In addition to AWS D1.1 mandated
storage requirements, research indicates that certain FCAW electrodes may warrant protected storage or
limited atmospheric exposure times. Such controls and limitations should be based upon manufacturer’s
test data and recommendations.
C
c. Prior to Welding. Prior to the actual start of welding on the project, item c(1) below should be
performed. All other inspection items should be performed prior to beginning the welding of each joint. It
is not anticipated that the inspector physically perform these inspections at each individual joint, but will
verify that the contractor’s personnel understand and routinely perform these inspections as a part of
their welding operations. This may be done through observation of welding operations and informal
inquiries of welding personnel. The inspector may, when desired, perform any physical inspections prior
to welding to verify the contractor personnel’s work.
(1) Pre-project review. Prior to the beginning of actual welding on the project, it should be verified
that all non-compliance revealed during pre-project inspection has been rectified.
(2) Base metal quality. Steel joints to be welded must be smooth, uniform, and free from significant
surface discontinuities such as cracks or seams, and free of significant amounts of loose or thick scale,
slag, rust, moisture, grease, or other harmful foreign materials. See AWS D1.1 Section 5.15 for complete
base metal preparation requirements.
8-6
CEMP-E
TI 809-26
1 March 2000
(3) Fillet weld fitup. Fillet welded joints must be fitup with a maximum gap of 1.6 mm (1/16 in.),
unless corrective measure are taken. For gaps exceeding 1.6 mm (1/16 in.), but not to exceed 5 mm
(3/16 in.), the leg size of the weld must be increased by an amount equal to the gap. Gaps over 5 mm
(3/16 in.) are permitted only for steels over 76 mm (3 in.) in thickness, when suitable backing is placed in
the root of the joint, and the fillet leg size is increased. See AWS D1.1 Section 5.22.1.
ED
(4) Groove weld fitup. Prequalified groove welds must be assembled within the “as fit-up” tolerance
specified for the joint in AWS D1.1 Figures 3.3 and 3.4. For Partial Joint Penetration (PJP) groove welds,
assembly tolerances are provided in AWS D1.1 Section 5.22.2. For other groove dimension tolerances
applicable to other groove welds, see AWS D1.1 Section 5.22.4.1.
EL
L
(5) Steel temperature. The temperature of the steel at the joint prior to the initiation of welding
must not be below 0 oC (32oF). When steel temperatures are below these minimum temperatures, it is
necessary to heat the steel in the vicinity of the joint to at least 21 oC (70oF). See AWS D1.1 Table 3.2,
Note 1. For prequalified steels listed in AWS D1.1 Table 3.2, as Category C steels, the minimum steel
temperature at the joint is 10 oC (50oF). Steels of thicknesses requiring preheat, per AWS D1.1 Table 3.2,
require higher temperatures. After heating, the temperature of the steel should be measured a distance
75 mm (3 in.) away from the joint. For welding in extreme cold environments, it is advisable to heat the
steel to higher temperatures and apply the heat over a wider area.
(6) Ambient temperature. Welding is not permitted when the ambient (air) temperature is below 18oC (0oF), or when welding personnel are exposed to inclement environmental conditions. Protective
covering or enclosures, with heating as necessary, may be used to satisfy this requirement and provide
adequate protection and warmth for the welders and welding equipment.
AN
C
(7) Wind speed. Gas-shielded welding processes (FCAW-G, GMAW, GTAW, and EGW) may not
be performed in winds exceeding 8 km per hour (5 mph), as wind above this speed blows away the
necessary shielding gas and contributes to poor weld quality and poor mechanical properties. For selfshielded welding processes (SMAW, FCAW-S, SAW, and ESW), the maximum wind speed is not
specified by AWS D1.1, but should be limited to a maximum of 30 to 40 km per hour (20 to 25 mph).
See AWS D1.1 Section 5.12 for welding environment provisions.
(8) WPS, including preheat. The inspector should verify compliance of the welding consumables
selected (electrode, flux and shielding gas) with the project requirements and the WPS. The selected
electrodes should be taken only from proper storage, and used only in the permitted positions and within
the welding parameters specified by the manufacturer and in the WPS. It should be verified that the
WPS is appropriate for the joint, within any specified limitations.
C
(9) Preheat. Preheat temperatures as specified in the WPS must be provided and checked for
compliance with AWS D1.1 Table 3.2 if prequalified. Higher preheat temperatures may be specified. It
may also be necessary to verify that the preheat temperature does not exceed any maximum values
specified in the WPS, sometimes required for quenched and tempered, TMCP, or other special steels, or
when toughness requirements apply. Verification of preheat temperature should be taken 75 mm (3 in.)
from the joint, provided the thickest material joined is 75 mm (3 in.) or less in thickness. If the steel is
thicker, then the temperature verification is taken a distance equal to the material thickness.
Temperatures may be checked with surface temperature thermometers, close-range focused infrared
devices, or with temperature-indicating crayons.
(10) Tack welds. Tack welds must be made using appropriate WPSs, including preheat when
required. Tack welds should be visually inspected prior to being welded over by the finish weld. Cracks in
8-7
CEMP-E
TI 809-26
1 March 2000
tack welds are likely to propagate into the main weld. Slag that has not been removed will likely result in
slag inclusions in the completed weld.
ED
d. During Welding. Observation of welding techniques and performance for each welder should be
done periodically during welding operations to verify that the applicable requirements of the WPS and
the AWS D1.1 Code are met. Each pass should be visually inspected by the welder for conformance to
AWS D1.1 Table 6.1 provisions for cracks, fusion and porosity prior to placement of subsequent passes.
To avoid trapped slag, penetration and fusion discontinuities, each weld bead profile should be in
substantial conformance with the requirements of Table 6.1.
(1) WPS compliance. The inspector should verify that the welding is performed following the
appropriate Welding Procedure Specification (WPS). If desired, proper current (amperage) and voltage
for the welding operation may be verified using a hand held calibrated amp and volt meter. Because of
welding lead losses, measurement should as near the arc as practical. Welds not executed in
conformance with the WPS may be considered rejectable, and should be referred to a knowledgeable
welding consultant and the Engineer for review.
EL
L
(2) Interpass temperatures. Interpass temperatures as specified in the WPS must be provided and
checked with compliance with AWS D1.1 Table 3.2 if a prequalified groove weld joint. Higher preheat
temperatures may be specified. It may also be necessary to verify that the interpass temperature does
not exceed any maximum values specified in the WPS, sometimes specified for quenched and
tempered, TMCP, or other special steels, or when toughness requirements apply. Verification of
interpass temperature should be taken 75 mm (3 in.) from the joint, provided the thickest material joined
is 75 mm (3 in.) or less in thickness. Temperatures may be checked with surface temperature
thermometers, close-range focused infrared devices, or with temperature-indicating crayons.
AN
C
(3) Consumables control. Exposure of SMAW electrodes and SAW fluxes must meet the time
limitations of AWS D1.1 Section 5.3. See AWS D1.1 Table 5.1 for SMAW electrode exposure limits.
SAW fluxes may require drying, special handling, recycling, and removal of exposed flux from opened
packages. Although not limited by AWS D1.1, research indicates that some FCAW electrodes may
absorb moisture in the order of 50% of the “as-manufactured” moisture content. When extra-low
hydrogen welding electrodes are required for critical welding applications, and FCAW wires removed
from the manufacturer’s packaging will not be consumed within a few days, special storage conditions
limiting exposure times, repackaging unused FCAW wire in closed moisture-resistant packing overnight,
or the use of storage ovens, may be appropriate. AWS D1.5 Bridge Welding Code, Section 12 provisions
for Fracture Critical Nonredundant Members should be considered for guidance in special cases.
C
(4) Cleaning. Completed weld passes must be cleaned of all slag prior to placement of the next
pass. Removal of debris by brushing is required. Wire brushing of the completed weld is recommended,
but not required. Slag that has not been removed will likely result in slag inclusions in the completed
weld. See AWS D1.1 Section 5.30.
e. After Welding. After completion of the weld, full compliance with the AWS D1.1 provisions should
be verified. If required or specified, NDT is to be performed. Upon completion of inspection of the weld,
piece, or project, as appropriate, proper documentation of the acceptance of the welding should be
prepared and submitted to the designated parties.
(1) Measurement. The work should be visually inspected for conformance with the Visual
Inspection Acceptance Criteria prescribed in AWS D1.1 Table 6.1. These provisions prohibit cracks and
lack of fusion, and permit limited amounts of undercut, porosity, and weld size underrun. Weld profile
8-8
CEMP-E
TI 809-26
1 March 2000
tolerances are provided in AWS D1.1 Figure 5.4, and Section 5.24. Size and contour of welds should be
measured with suitable gauges. Craters are accepted in certain circumstances. Other weld acceptance
criteria that is verified visually include arc strikes (AWS D1.1 Section 5.29), and weld cleaning (Section
5.30). Visual inspection may be aided by a strong light, magnifiers, or other devices that may be helpful.
(2) Tolerances. The tolerances for the completed member, including cross-section, depth, camber,
sweep, straightness, flatness, flange warpage and tilt, stiffener fit, and bearing surface fit, are prescribed
in AWS D1.1 Section 5.23.
ED
(3) Records. The Inspector should mark the welds, joints, or members, as appropriate, that have
been inspected and accepted using a distinguishing mark or die stamp. Alternatively, records indicating
the specific welds inspected by each person may be maintained. The accepted, rejected and repaired
items should be documented in a written report, distributed to the designated recipients in a timely
manner.
EL
L
f. Nondestructive Testing Methods. AWS D1.1 does not require NDT for statically-loaded building
structures, but NDT is required by both AISC and AWS D1.1 for certain fatigue detail categories for
cyclically-loaded structures. AISC Seismic Provisions require NDT for certain joints in high seismic
applications, as follows: “All complete joint penetration and partial joint penetration groove welded joints
that are subjected to net tensile forces as part of the Seismic Force Resisting Systems ... shall be tested
using approved nondestructive testing methods conforming to AWS D1.1.” Such testing should include
ultrasonic testing of welds in T-joints and butt joints over 8 mm (5/16 in.) in thickness. Radiographic
testing may be used in some cases using butt joints. When using T-joints, with the thickness of the tee
“flange” exceeding 40 mm (1-1/2 in.), ultrasonic testing should be performed after completion and
cooling to check for lamellar tearing.
C
(1) The specific types of NDT, and the applicable acceptance criteria, must be specified in the
contract documents. NDT symbols should be used to specify locations and types of NDT. See AWS A2.4
Part C.
AN
(2) The contractor is responsible for performing any required NDT, unless specifically designated
to be performed by another party.
(3) Because of the risk of delayed hydrogen cracking, a delay period of 24 to 48 hours should be
considered prior to performing NDT for final acceptance for higher strength steels. See AWS D1.1 Table
6.1 (5). The AWS D1.5 Bridge Welding Code Section 12.16.4 requires a longer delay period for Fracture
Critical Members, depending upon weld size and steel strength.
C
(4) Tables 8-1 and 8-2 provide general guidance for the selection of NDT method(s). For complete
information, see Appendix D.
8-9
CEMP-E
TI 809-26
1 March 2000
Table 8-1. Applicable Inspection Methods for Various Discontinuities and Joint
Types
Porosity
Slag Inclusions
Incomplete Fusion
Inadequate Joint Penetration
Undercut
Overlap
Cracks
Laminations
J
o
i
n
t
s
Butt
Corner
T
Lap
MT
UT
RT
A1
U
U
U
A
O
A1
A1,3
A1
U
U
U
O
A
A1
A1,3
O2
O2
U
U
O
A
A2
A2,3
O
A
A
A
O
O
A
A
A
A
O
A
A
U
O
U
A
A
A
A
A
A
A
A
A
A
A
O
A
O
O
U
C
A
A
A
A
AN
Notes:
PT
EL
L
D
i
s
c
o
n
t
i
n
u
i
t
y
VT
ED
Application
Inspection Method
A - Applicable
O - Marginal applicability, depending upon material thickness, discontinuity size,
orientation, and
location.
U - Generally not applicable.
Surface only
Surface and slightly subsurface only
3
Weld preparation or edge of base metal
1
C
2
8-10
CEMP-E
TI 809-26
1 March 2000
Table 8-2. Guidelines for Selecting Inspection Techniques
VT
PT
MT
UT
RT
Pocket
magnifier,
flashlight, weld
gauges, scale,
etc.
Fluorescent or
visible
penetration
liquids and
developers;
ultraviolet light
for fluorescent
dyes
Wet or dry iron
particles, or
fluorescent;
special power
source;
ultraviolet light
for fluorescent
particles
Ultrasonic
units and
probes;
reference
patterns
X-ray or
gamma-ray;
film
processing
and viewing
equipment
D
e
t
e
c
t
i
o
n
Weld
preparation, fitup, cleanliness,
roughness,
spatter,
undercut,
overlap, weld
contour and size
Discontinuities
open to the
surface only
Surface and
near surface
discontinuities:
cracks;
porosity; slag
Can locate
all internal
discontinuiti
es located by
other
methods, as
well as small
discontinuiti
es
Most internal
discontinuiti
es; limited
by direction
of
discontinuity
A
d
v
a
n
t
a
g
e
s
Easy to use; fast;
inexpensive;
usable at all
stages of
production
Detects small
surface
imperfections;
easy
application;
inexpensive;
low cost
Detects
discontinuities
not visible to
the naked eye;
useful for
checking edges
before welding;
no size
limitations
Extremely
sensitive;
complex
weldments
restrict
usage
Provides
permanent
record of
surface and
internal
discontinuiti
es
Timeconsuming; not
permanent
Surface
roughness may
distort
magnetic field;
not permanent
Highly skilled
interpreter
required; not
permanent
Usually not
suitable for
fillet weld or
T-joint
inspection;
film
exposure
and
processing
critical; slow
and
expensive
EL
L
C
AN
For surface
conditions only;
dependent on
subjective
opinion of
inspector
C
L
i
m
i
t
a
t
i
o
n
s
ED
E
q
u
i
p
t
m
e
n
t
8-11
CEMP-E
Most universally
used inspection
method
Indications may
be misleading
on poorly
prepared or
cleaned
surfaces
Test from two
perpendicular
directions to
detect any
indications
parallel to one
set of magnetic
lines
Radiation
hazards
C
AN
C
EL
L
ED
C
o
m
m
e
n
t
s
TI 809-26
1 March 2000
8-12
CEMP-E
TI 809-26
1 March 2000
6. WELD QUALITY.
ED
a. Engineer’s Responsibility for Acceptance Criteria. The Engineer is given the responsibility of
determining and specifying the appropriate weld quality acceptance criteria. AWS D1.1 quality criteria is
a workmanship standard, based upon the quality readily achievable by a qualified welder. Nondestructive testing acceptance criteria is based upon achievable quality and the ability of the method to
detect discontinuities of given size and location, with some consideration for the effect of surface and
near-surface notches upon performance. The Engineer may use experience, analysis, or experimental
evidence to establish alternate acceptance criteria. This criteria may be applied as the inspection criteria
for the project, in lieu of AWS D1.1 criteria, or may be used to establish when repair or replacement of a
weld is required for a given discontinuity or situation. The first approach is valuable because it reduces
the time and expense of inspection, and eliminates needless repairs, reducing the risk of creating
additional discontinuities while performing repairs, and reduces the potential detrimental effects to the
existing base metal. The second approach is also valuable, but does not reduce inspection expense. See
AWS D1.1 Section C6.8.
Weld Discontinuity
Crack
Fusion
AWS D1.1 References
Table 6.1 (1)
Table 6.1 (2)
Table 6.1 (3)
Table 6.1 (4), 5.24
Weld Size (underrun, lack of penetration, underfill)
Table 6.1 (6), 6.5.1
Undercut
Table 6.1 (7)
Porosity
Table 6.1 (8)
Arc Strike
5.29
Surface Slag
5.30
Spatter
5.30.2
Length
6.5.1
Location
6.5.1
AN
Weld Profile (convexity, concavity, overlap,
reinforcement)
C
C
Weld Craters
EL
L
b. D1.1 Visual Acceptance Criteria. The following table provides the specification reference location
for various forms of weld discontinuities:
c. NDT Acceptance Criteria. When penetrant testing (PT), and magnetic particle testing (MT) are
specified, the acceptance criteria to be used is the same as that for visual inspection. For ultrasonic
8-13
CEMP-E
TI 809-26
1 March 2000
testing (UT), the visual inspection criteria is applicable, plus the requirements of AWS D1.1 Section 6.13.
For radiographic testing (RT), the visual inspection criteria is applicable, plus the requirements of AWS
D1.1 Section 6.12.
ED
d. Alternate Acceptance Criteria. The Engineer may base alternate weld quality acceptance criteria on
experience, experimental results, structural analysis, or fracture mechanics analysis considering material
properties and behavior, service and fracture loads and strengths, and environmental factors. Sources of
information to assist in the development of alternate acceptance criteria are provided in Appendix B,
Bibliography.
7. REPAIRS TO BASE METAL AND WELDS.
EL
L
a. Mill Defects. ASTM A6 Section 9, requires only visual inspection by the mill of the completed
product for defects in workmanship. Subsurface inspection for laminations and other defects, such as
straight-beam ultrasonic testing, would be performed only when specified in the mill order, at extra cost.
The mill is permitted to perform removal and repairs to the surface using various means such as grinding
and welding, to limits specified in ASTM A6 Section 9. During fabrication, should unacceptable internal
discontinuities be discovered in the steel, the steel may be considered rejectable. The size or type of
internal discontinuity considered rejectable is not defined by specification.
C
b. Laminations. When internal laminations in the steel are discovered during fabrication, AWS D1.1
Section 5.15.1, provides procedures for the investigation and repair of the exposed laminations. All
exposed laminations must be explored for depth. Shallow laminations need not be repaired, but longer
and deeper laminations will need either removal by grinding or welding to close the lamination prior to
welding the joint. Laminations at welded joints may serve as sources of porosity and as crack initiation
points.
AN
c. Weld Discontinuities. For welds with unacceptable convexity, excessive reinforcement, or overlap,
the weld should have the excess weld metal removed. This is typically done by grinding, but may be
done by gouging. For undersized welds, including craters, the weld should be filled to the required size.
Some craters may be acceptable if outside the required effective length of weld. For excessive undercut,
the undercut portion should be filled using an approved repair procedure. For cracks, lack of fusion, and
excessive porosity, the unacceptable portion must be completely removed and replaced. Additional
caution should be used when repairing cracks. The end of the crack should be located using PT or MT,
then crack removal should begin approximately 50 mm (2 in.) from the end of the crack and work toward
the center of the crack. Starting within the crack may cause the crack to grow during removal. See AWS
D1.1 Section 5.26.1. Should it be necessary to cut the materials apart, the Engineer must be notified.
C
d. Root Opening Corrections. Root openings that are too narrow must be increased in width to the
required root opening. Narrow root openings contribute to trapped slag, poor penetration and lack of
fusion near the root. Repairs for narrow root openings may be done by grinding, chipping, air carbon arc
gouging, if refitting the parts is not feasible. Root openings that are too wide are significant in that they
increase the weld volume, increasing distortion and increasing the risk of lamellar tearing in T-joints, as
well as increasing cost. A root pass placed across a wide root opening may develop shrinkage cracks in
the HAZ or in the throat of the weld. Repair of wide root openings entails facing the groove with weld
metal until the required root opening is achieved. Such a repair does not reduce volume or cost, but
controls distortion and through-thickness strains in T-joints. An alternative to repair of this type would be
to use split-layer techniques for the root pass, and subsequently control bead placement to minimize
shrinkage and distortion effects.
8-14
CEMP-E
TI 809-26
1 March 2000
C
AN
C
EL
L
ED
e. Mislocated Holes. When holes have been mislocated, it is best to either leave the hole unfilled or to
place a bolt in the hole. It is difficult to fill a hole by welding. When the hole must be filled, generally
when a new hole must be placed near or adjacent to the misplaced hole, a special repair procedure
should be followed to elongate the hole, then weld using stringer passes. NDT may be necessary after
welding, if required elsewhere on the project for groove welds. NDT is required for repair welds for holes
in cyclically loaded members. See AWS D1.1 Section 5.26.5.
8-15
CEMP-E
TI 809-26
1 March 2000
CHAPTER 9
OTHER WELDING SPECIFICATIONS AND STANDARDS
ED
1.TUBULAR STRUCTURES. For the welding of tubular members, also referred to as hollow structural
sections, refer to ANSI/AWS D1.1 tubular provisions and the AISC Connections Manual for Hollow
Structural Sections. These documents apply to the specific requirements of tube-to-tube applications, but
are also applicable to tube-to-plate applications.
EL
L
2. SHEET STEEL WELDING. For welding steel materials less than 3.2 mm (1/8 in.) in thickness, refer to
ANSI/AWS D1.3 Structural Welding Code - Sheet Steel, and the AISI Specification for the Design of
Cold-Formed Steel Structural Members for general design provisions. Sheet steels equal to or greater
than 3.2 mm (1/8 in.) thick, but less than or equal to 4.8 mm (3/16 in.) thick, may be welded under either
AWS D1.3 or AWS D1.1.
3. REINFORCING STEEL. For welding reinforcing steel, including mats, fabric, metal inserts and
connections in reinforced concrete construction, refer to ANSI/AWS D1.4 Structural Welding Code Reinforcing Steel. For reinforcing steel welded to structural steel, AWS D1.4 must be met for the weld,
but any applicable provisions, such as preheat requirements, based upon the structural steel must also
be met.
C
4. STAINLESS STEEL. For welding of stainless steels, refer to ANSI/AWS D1.6 Structural Welding Code
- Stainless Steel. This code includes welding of hot- and cold-rolled sheets and plate, shapes, tubular
members, clad materials, castings and forgings of stainless steels. It is not applicable to pressure vessels
or pressure piping with pressures exceeding 104 kPa (15 psig).
AN
5. ALUMINUM. For the welding of structural aluminum alloys, refer to ANSI/AWS D1.2 Structural
Welding Code - Aluminum.
C
6. BRIDGES. For the welding of highway bridges designed for vehicular traffic, refer to the
ANSI/AASHTO/AWS D1.5 Bridge Welding Code, including the Fracture Control Plan for nonredundant
bridge members, if applicable.
7. MATERIAL HANDLING EQUIPMENT. For the welding of material handling equipment, refer to
ANSI/AWS D14.1 Specification for Welding Industrial and Mill Cranes and Other Material Handling
Equipment. This specification applies to the welding of all principal structural weldments and all primary
welds used in the manufacture of cranes for industrial, mill, powerhouse and nuclear facilities. It also
applies to other overhead material handling machinery and equipment that supports and transports
loads.
8. CAST STEEL. See Appendix B - Bibliography.
9-1
CEMP-E
TI 809-26
1 March 2000
9. CAST IRON. See Appendix B - Bibliography.
10. WROUGHT IRON. See Appendix B - Bibliography.
ED
11. OTHER GOVERNING SPECIFICATIONS
a. ASME. For the welding of pressure vessels, refer to ANSI/ASME BPVC, Boiler and Pressure
Vessel Code, Section 9, Welding and Brazing Qualifications.
EL
L
b. API. For the welding of offshore structures, refer to the API RP 2A series documents, Planning,
Designing and Constructing Fixed Offshore Platforms. For the welding of pipelines, refer to API Standard
1104, Welding of Pipelines and Related Facilities. For the welding of storage tanks, refer to API 12D Field
Welded Tanks for Storage of Production Liquids, or API 12F, Shop Welded Tanks for Storage of
Production Liquids.
C
AN
C
c. AWWA. For the welding of water tanks, refer to AWWA Manual M42, Steel Water Storage
Tanks .
9-2
CEMP-E
TI 809-26
1 March 2000
CHAPTER 10
SAFETY AND ENVIRONMENTAL CONSIDERATIONS
1. GENERAL.
ED
The following provisions should not be considered all-inclusive, complete, or exclusive. Refer to
applicable governing documents for complete information.
2. SAFETY.
move the object to receive the work away from combustible materials
move the combustible materials at least 15 m (50 ft.) from the welding or cutting operation
provide suitable fire-resistant shielding around the work area or combustible material
fire extinguishing equipment should be accessible to welding personnel
trained fire watch personnel should be used if the operations are performed near
combustible materials.
C
•
•
•
•
•
EL
L
a. Fire. Welding, thermal cutting, and arc gouging operations produce molten metal that may cause
burns, fires, or explosion. The fuel gases used pose no hazard, provided they are handled and stored in
a safe and proper manner. Oxygen for oxyfuel cutting is not flammable by itself, but will contribute to
more intense fires if pure oxygen is available. SMAW electrode stubs are very hot and could cause a fire
if carelessly thrown on wood or paper products. Poor quality or poorly maintained electrical connections
can cause overheating or sparking and subsequent ignition. During operations, molten steel, sparks and
spatter often travel a considerable distance, risking a fire in nearby flammable materials. The following
safety guidelines should be considered:
AN
b. Confined Spaces. Work in confined spaces requires additional safety precautions. A confined
space could be a tank, pit, etc. that does not allow for adequate ventilation for the removal of hazardous
gases or fumes resulting from the work. Certain welding processes use gases such as argon, helium,
carbon dioxide or nitrogen which will not support life. Deaths and severe injuries due to lack of oxygen
have occurred where the concentration of these gases becomes too high, (i.e.,where the available
oxygen is too low).The following additional safety guidelines should be considered:
remove flammable or hazardous materials from the space,
provide adequate ventilation air to the space,
test the atmosphere in the space before and during the work,
inspect all electrical cables and connections,
test all fuel gas and shielding gas lines for leaks,
cutting torches must not be lit or extinguished within the space,
no compressed gas cylinders or welding power sources may be placed inside the space,
electrical power must be disconnected and all gas valves closed when work is suspended for
any substantial period of time,
if only a small opening is available for entry, the welder must wear an approved safety harness
equipped with a rope or lifeline, tied off and held by a worker stationed outside the space.
C
•
•
•
•
•
•
•
•
•
c. Eye Protection. The arc produced from welding or air carbon arc gouging may burn the eyes.
Proper filters and cover plates must be worn to protect the eyes from sparks and the rays of the arc.
10-1
CEMP-E
TI 809-26
1 March 2000
d. Burn protection. Arc burn may be more severe than sunburn. Molten metal, sparks, slag, and hot
material can cause severe burns if precautionary measures are not used. Protect the skin against
radiation and hot particles, electrodes, and metal. Suitable flame-resistant clothing must be worn as
protection from sparks and arc rays.
ED
e. Electrocution. The electrode, electrode reel (for wire-fed processes), and workpiece (or ground) are
considered electrically “hot” when the welder is on. These parts must not be touched with bare skin or
wet clothing. Dry, hole-free gloves are necessary. The work piece and welding equipment must be
grounded.
f. Fumes and Gases.
EL
L
(1) Many welding, cutting and allied processes produce fumes and gases that may be harmful.
Fumes are solid particles that originate from welding consumables, the base metal and any coatings
present on the base metal. In addition to shielding gases that may be used, gases are produced during
the welding process or may be produced by the effects of process radiation on the surrounding
environment. The amount and composition of these fumes and gases depend upon the composition of
the filler metal and base material, welding process, current level, arc length and other factors.
C
(2) Most welding fumes from carbon steel and low alloy steel electrodes do not require any
attention to limits for any specific compound or compounds. The compounds in the fume such as oxides
and fluorides of aluminum, calcium, iron, magnesium, potassium, silicon (which is amorphous in welding
fumes), sodium, and titantium, do not have individual effects, except that excessive iron may cause
siderosis (iron deposits in the lungs). Their effects are submerged in the overall effects which may be
expected from nuisance dusts.
.
(3) Some specific fume components such as chromium, cobalt, copper, fluorides, manganese, and
nickel are present in some electrodes, require special attention, and have special health hazards. When
these are present at levels of concern, they are listed on the product label and in the MSDS. Their health
hazards are discussed in the MSDS.
AN
(4) Depending on material involved, fume effects range from irritation of eyes, skin and respiratory
system to more severe complications and may occur immediately or at some later time. Fumes may also
cause symptoms such as nausea, headache, and dizziness.
C
(5) The following safety guidelines should be considered, as a minimum:
• Keep the head out of the fumes.
• Do not breathe the fumes.
• Use enough ventilation or exhaust at the arc, or both, to keep fumes and gases from the
breathing zone and general area.
• In some cases, natural air movement provides enough ventilation and fresh air.
• Where ventilation is questionable, use air sampling to determine the need for corrective
measures.
• Use mechanical ventilation when necessary to improve air quality.
• If engineering controls are not feasible, use an approved respirator.
• Follow OSHA guidelines for permissible exposure limits (PELs) for various fumes.
• Follow the American Conference of Governmental Industrial Hygienists recommendations
for threshold limit values (TLVs) for fumes and gases.
g. Further Guidance. See ANSI / AWS Z49.1 Safety in Welding, Cutting and Allied Processes, and
10-2
CEMP-E
TI 809-26
1 March 2000
the Bibliography in Appendix B for further general information. The Material Safety Data Sheet (MSDS)
for each product used also provides essential information.
3. ENERGY CONSUMPTION.
C
AN
C
EL
L
ED
Shop welding operations are almost always electrically powered. Field operations may be electrically
powered or powered by generators. Some field welding equipment is directly engine driven. Power
requirements depend more upon electrode diameter than welding process. SMAW, FCAW and GMAW
welding equipment draws essentially the same current ranges, and SAW, ESW and EGW draws more
current to provide the higher deposition rates achievable and desired. The total power consumption
difference between processes for a given joint configuration is negligible. To save energy, the minimum
weld size and minimum groove cross-sectional area adequate to carry the load should be specified.
10-3
CEMP-E
TI 809-26
1 March 2000
APPENDIX A
REFERENCES
GOVERNMENT PUBLICATIONS
United States Army Corps of Engineers
ED
TI 800-01, Design Criteria
TI 809-01, Load Assumptions for Buildings
TI 809-02, Structural Design Criteria for Buildings
TI 809-04, Seismic Design for Buildings
TI 809-05, Seismic Evaluation and Rehabilitation for Buildings
TI 809-07, Design of Cold-Formed Load Bearing Steel Systems and Masonry Veneer / Steel Stud Walls
TI 809-30, Metal Building Systems
Department of the Army
EL
L
MIL-HDBK-1002/1, Structural Engineering, General Requirements
MIL-HDBK-1002/3, Structural Engineering, Steel Structures
MIL-HDBK-1002/6, Aluminum Structures, Composite Structures, Structural Plastics, and FiberReinforced Composites.
C
TM 5-809-6, Structural Design Criteria for Structures Other Than Buildings (to become TI 809-6)
Federal Emergency Management Agency (FEMA)
AN
FEMA 267, Interim Guidelines: Evaluation, Repair, Modification and Design of Steel Moment Frames,
August 1995
FEMA 267B, Interim Guidelines Advisory No. 2
FEMA 273, NEHRP Guidelines for the Seismic Rehabilitation of Buildings, October 1997
FEMA 302, NEHRP Recommended Provisions for Seismic Regulations for New Buildings and Other
Structures, February 1998
C
NONGOVERNMENT PUBLICATIONS
American Institute of Steel Construction
One East Wacker Drive, Suite 3100
Chicago, IL 60601-2001
www.aisc.org
Metric Load and Resistance Factor Design Specification for Structural Steel Buildings, December 1,
1994
(Supplement No. 1, January 30, 1998)
(new specification to be issued in early 2000)
Load and Resistance Factor Design Specification for Structural Steel Buildings, December 1, 1993
(Supplement No. 1, January 30, 1998)
A-1
CEMP-E
TI 809-26
1 March 2000
EL
L
American Society for Testing and Materials (ASTM)
100 Barr Harbor Drive
West Conshohocken, PA 19428
www.astm.org
ED
(new specification to be issued in early 2000)
Specification for Structural Steel Buildings (Allowable Stress Design and Plastic Design), June 1, 1989
Seismic Provisions for Structural Steel Buildings, April 15, 1997
(Supplement No. 1, February 15, 1999)
Specification for Load and Resistance Factor Design of Single-Angle Members, December 1, 1993
Specification for the Design of Steel Hollow Structural Sections, April 15, 1997
Code of Standard Practice for Steel Buildings and Bridges, June 10, 1992
Metric Conversion of the 2nd Edition Manual of Steel Construction, Load and Resistance Factor Design,
2nd Edition, Volumes I and II, 1999
Manual of Steel Construction, Load and Resistance Factor Design, 2 nd Edition, Volumes I and II, 1994
Manual of Steel Construction, Allowable Stress Design, 9 th Edition, 1989
Manual of Steel Construction, ASD/LRFD, Volume II Connections, 1992
Hollow Structural Sections Connections Manual, 1997
Annual Book of Standards
Volume 1.04, Steel - Structural, Reinforcing, Pressure Vessel, Railway
Volume 3.03, Nondestructive Testing
C
American Welding Society
550 NW LeJeune Road
Miami, FL 33126
www.aws.org
C
AN
ANSI/AWS D1.1-98, Structural Welding Code - Steel
ANSI/AWS D1.3-98, Structural Welding Code - Sheet Steel
ANSI/AWS D1.4-98, Structural Welding Code - Reinforcing Steel
ANSI/AASHTO/AWS D1.5-96, Bridge Welding Code
ANSI/AWS D1.6-98, Structural Welding Code - Stainless Steel
ANSI/AWS A2.4-98, Standard Symbols for Welding, Brazing, and Nondestructive Testing
ANSI/AWS A3.0-94, Standard Welding Terms and Definitions
ANSI/AWS A5.1-91, Specification for Carbon Steel Electrodes for Shielded Metal Arc Welding
ANSI/AWS A5.5-96, Specification for Low–Alloy Steel Electrodes for Shielded Metal Arc Welding
ANSI/AWS A5.17/A5.17M-97, Specification for Carbon Steel Electrodes and Fluxes for Submerged Arc
Welding
ANSI/AWS A5.18-93, Specification for Carbon Steel Electrodes and Rods for Gas Shielded Arc Welding
ANSI/AWS A5.20-95, Specification for Carbon Steel Electrodes for Flux Cored Arc Welding
ANSI/AWS A5.23/A5.23M-97, Specification for Low-Alloy Steel Electrodes and Fluxes for Submerged
Arc Welding
ANSI/AWS A5.25/A5.25M-97, Specification for Carbon and Low-Alloy Steel Electrodes and Fluxes for
Electroslag Welding
ANSI/AWS A5.26/A5.26M-97, Specification for Carbon and Low-Alloy Steel Electrodes for Electrogas
Welding
ANSI/AWS A5.28-96, Specification for Low-Alloy Steel Electrodes and Rods for Gas Shielded Arc
A-2
CEMP-E
TI 809-26
1 March 2000
American Society for Nondestructive Testing, Inc.
PO Box 28518
Columbus, OH 43228-0518
www.asnt.org
ED
Welding
ANSI/AWS A5.29-98, Specification for Low-Alloy Steel Electrodes for Flux Cored Arc Welding
ANSI/AWS A5.32/A5.32M-97, Specification for Welding Shielding Gases
ANSI/AWS Z49.1:1999, Safety in Welding, Cutting and Allied Processes
C
AN
C
EL
L
ANSI/ASNT CP-189-1995, ASNT Standard for Qualification and Certification of Nondestructive Testing
Personnel
Recommended Practice No. SNT-TC-1A, Personnel Qualification and Certification in Nondestructive
Testing, 1995
A-3
CEMP-E
TI 809-26
1 March 2000
APPENDIX B
BIBLIOGRAPHY
Welding Cracks Investigation Report, Steel Special Moment Resisting Frames, Elmendorf Air Force
Base Hospital, Anchorage, Alaska, December 1996
EL
L
ED
American Institute of Steel Construction
Allowable Stress Design of Simple Shear Connections, 1990
Engineering and Quality Criteria for Steel Structures, 4 th Edition, 1997
Engineering Journal, Experimental Investigation of Dogbone Moment Connections (Engelhart, et al),
Vol 35, No 4, 4 th Qtr 1998
Engineering Journal, Ultimate Strength Considerations for Seismic Design of the Reduced Beam
Section (Internal Plastic Hinge) (Iwankiw), Vol 34, No 1, 1 st Qtr 1997
Engineering and Quality Criteria for Steel Structures, 4 th Edition, 1997
Load and Resistance Factor Design of Simple Shear Connections, 1990
American Petroleum Institute
API 12D, Field Welded Tanks for Storage of Production Liquids (1994)
API 12F, Shop Welded Tanks for Storage of Production Liquids (1994)
API RP 2A series documents, Planning, Designing and Constructing Fixed Offshore Platforms
API Standard 1104, Welding of Pipelines and Related Facilities, 18 th Ed. (1994)
AN
C
American Society for Metals
ASM Handbook, Volume 1: Properties and Selection: Irons, Steels, and High-Performance Alloys,
1990
ASM Handbook, Volume 6: Welding, Brazing and Soldering, 1993
ASM Metals Handbook, 2 nd Ed., 1998
ASM Specialty Handbook: Carbon and Alloy Steels, 1996
ASM Specialty Handbook: Cast Irons, 1996
Steel Castings Handbook, 6 th Ed., 1995
Weld Integrity and Performance, 1997
C
American Society for Nondestructive Testing
Nondestructive Testing Handbook
Volume 2: Liquid Penetrant Tests, 2 nd Ed, 1982
Volume 3: Radiography and Radiation Testing, 2 nd Ed, 1985
Volume 6: Magnetic Particle Testing, 2 nd Ed, 1989
Volume 7: Ultrasonic Testing, 2 nd Ed, 1991
Volume 8: Visual and Optical Testing, 2 nd Ed, 1993
American Society of Mechanical Engineers
ANSI/ASME BPVC, Boiler and Pressure Vessel Code, Section 9, Welding and Brazing
Qualifications (1998)
American Water Works Association
AWWA Manual M42 Steel Water Storage Tanks (1998)
B-1
CEMP-E
TI 809-26
1 March 2000
EL
L
ED
American Welding Society
Guide for Nondestructive Inspection of Welds, ANSI/AWS B1.10-86
Guide for Visual Inspection of Welds, ANSI/AWS B1.11-88
Guide for Welding Iron Castings, ANSI/AWS D11.2-89
Oxygen Cutting Surface Roughness Gauge, AWS C4.1-G
Recommended Practices for Air Carbon Arc Gouging and Cutting, ANSI/AWS C5.3-91
Recommended Practices for Stud Welding, ANSI/AWS C5.4-93
Specification for Underwater Welding, ANSI/AWS D3.6-93
Specification for Welding Industrial and Mill Cranes and Other Material Handling Equipment,
AWS D14.1-97
Welding Handbook, 8th Edition
Volume 1, Welding Technology, 1987
Volume 2, Welding Processes, 1991
Volume 3, Materials and Applications, Part 1, 1996
Volume 4, Materials and Applications, Part 2, 1998
Welding Inspection, 1980
Welding Metallurgy, 4th Edition, Volume 1, Fundamentals, George E. Linnert, 1994
Welding of Cast Iron, 1985
C
Federal Emergency Management Agency
FEMA 288, Background Reports: Metallurgy, Fracture Mechanics, Welding, Moment Connections and
Frame Systems Behavior, March 1997
FEMA 303, NEHRP Recommended Provisions for Seismic Regulations for New Buildings and Other
Structures, February 1998
AN
Alternate Weld Quality Acceptance Criteria
British Standards Institution
BS PD-6493:1991, Guidance on methods for assessing the acceptability of flaws in structures
BS 7910: pending (1999), Guidance on methods for assessing the acceptability of flaws in
structures
Electric Power Research Institute
NP-5380, Visual Weld Acceptance Criteria
C
International Institute of Welding
IIW / IIS-SST-1157-90, IIW Guidance on Assessment of the Fitness for Purpose of Welded
Structures, Draft for Development, 1990
Welding Research Council
WRC Bulletin 295, Fundamentals of Weld Discontinuities and their Significance (Lundin), 1984
Design Aids for Welded Connections
American Institute of Steel Construction
AISC Manual of Steel Construction (ASD and LRFD versions)
Allowable Stress Design of Simple Shear Connections (1990)
CONXPRT (software)
B-2
CEMP-E
TI 809-26
1 March 2000
EL
L
ED
Load and Resistance Design of Simple Shear Connections (1990)
Module I - ASD Simple Shear Connections
Module I - LRFD Simple Shear Connections
Module II - ASD Moment Connections
Steel Detailing Software Packages with Connection Design
CDS
CompuSTEEL (Barasel Corp.)
CVSpro8 (CadVantage, Inc.)
DESCON (Omnitech Associates)
DETAIL (MacroSoft)
fabriCAD (Research Engineers, Inc.)
SDS/2 (Design Data, Inc.)
Steelcad (Steelcad International, Inc.)
StruCad (AceCad Software, Inc.)
StrucPro (Eagle Point)
Canadian Welding Bureau
Weld IT (software)
Safety and Health
American Conference of Governmental Industrial Hygienists (ACGIH)
Threshold Limit Values (TLV (R) ) for Chemical Substances and Physical Agents in the Workroom
Environment
C
American Welding Society, Fumes and Gases in the Welding Environment
National Fire Protection Association
Standard for Fire Prevention in Use of Cutting and Welding Processes: NFPA 51B, National Fire
Protection Association, 1994
AN
Occupational Safety and Health Administration (OSHA)
Code of Federal Regulations, Title 29, Labor, Chapter XV11, Parts 1901.1 to 1910.1450, Order No.
869-029-00222-5
C
Intermixed Weld Metal
The Effects of Intermixed Weld Metal on Mechanical Properties – Part 1, Quintana, M. A. and
Johnson, M. Q., Welding Journal, March 1999
The Effects of Intermixed Weld Metal on Mechanical Properties – Part 2, Quintana, M. A. and
Johnson, M. Q., Proceedings, AWS Annual Convention, Detroit, MI, 1998
The Effects of Intermixed Weld Metal on Mechanical Properties – Part 3, Quintana, M. A. and
Johnson, M. Q., Proceedings, AWS Conference on Welded Construction in Seismic Areas, Maui,
HI, 1998
B-3
CEMP-E
TI 809-26
1 March 2000
Welding Procedures
Heat-Straightening Repairs of Damaged Steel Bridges – A Technical Guide and Manual of Practice,
Report No. FHWA-IF-99-004, US Dept. of Transportation, Federal Highway Administration,
October 1998
Lincoln Electric Company, The Procedure Handbook of Arc Welding, 13 th Ed., 1994
ED
Reviewing and Approving Welding Procedure Specifications, Miller, D. K., Proceedings, AISC
National Steel Construction Conference, New Orleans, LA, April, 1998
What Every Engineer Should Know about Welding Procedures, Miller, D. K., Welding Journal, August
1999
EL
L
Other References and Textbooks
Cast Publishing
Metals Blue Book, Welding Filler Metals, 2 nd Ed, 1998
Metals Black Book, Ferrous Metals, 3 rd Ed, 1998
Metals Red Book, Nonferrous Metals, 2 nd Ed, 1998
Fracture and Fatigue Control in Structures, 2 nd Ed., Barsom, J. M. and Rolfe, S. T., Prentice-Hall,
1987
C
Lincoln Electric Co. / James F. Lincoln Arc Welding Foundation
Design of Welded Structures, 1966
Design of Weldments, 1976
Metals & How to Weld Them, 1962
The Procedure Handbook of Arc Welding, 13 th Edition, 1994
Tubular Steel Structures - Theory and Design, 1990
AN
Modern Welding Technology, 4th Ed., Cary, H. B., Prentice-Hall, 1997
C
Weldability of Steels, Stout, R. D. and Doty, W. D., Welding Research Council, 1953
B-4
CEMP-E
TI 809-26
1 March 2000
APPENDIX C
WELDING PROCESSES
1. SHIELDED METAL ARC WELDING (SMAW).
ED
a. Process Principles. The Shielded Metal Arc Welding (SMAW) process is commonly known as
“stick” welding, and is performed as “manual” welding. An electric arc is produced between the tip of the
electrode and the base metal, melting both. The molten weld pool, and completed weld, is a mixture of
base metal and electrode materials.
EL
L
(1) The core of the electrode is steel. The coating is of various materials designed to provide arc
stability, shield the molten weld puddle from atmospheric gases, flux the molten puddle of impurities,
deoxidize the molten weld puddle, and cover the solidifying weld to improve bead profile. Some coatings
contain metallic powders, adding specific alloys to the weld composition.
(2) SMAW may be operated using either DC (direct current) or AC (alternating current) polarity.
Generally, DC is used for smaller diameter electrodes, typically those with a diameter of less than 4.8
mm (3/16 in.). To eliminate undesirable arc blow conditions, larger electrodes are typically operated
using AC. Electrodes used on AC must be designed specifically to operate in this mode, where the
current changes direction 120 times per second on 60 Hertz power. AC electrodes may also operate
using either DCEN (DC Electrode Negative, DC-, also called “straight” polarity) or DCEP (DC Electrode
Positive, DC+, also called “reverse” polarity), and in some cases, either DC polarity.
C
b. Filler Metal Designation, Specification and Certification. Filler metal specification AWS A5.1
provides the requirements for carbon steel covered electrodes used with SMAW. AWS A5.5 similarly
covers the low-alloy steel electrodes for SMAW.
C
AN
(1) Generally, when welding on structural steels with a minimum specified yield strength equal to or
exceeding 485 MPa (50 ksi), SMAW electrodes should be of the low hydrogen type. See AWS D1.1
Table 3.1 lists specific steels and grades where the use of low hydrogen electrodes is required for the
prequalification of SMAW Welding Procedure Specifications (WPSs). Table 3.1 also provides the
strength of electrode required for these steels to provide the “matching” strength for the base metal.
Group I steels, including A36 steel, may be welded with non-low hydrogen electrodes. For Group II
steels, including A572 grade 50, and higher strength groups, low hydrogen electrodes are required. For
most structural steel fabrication today, low hydrogen electrodes are prescribed to offer additional
assurance against hydrogen induced cracking.
(2) Low hydrogen electrodes have coatings of inorganic materials that are very low in hydrogen,
and are designed to be extremely low in moisture. Water (H 2O) will break down into its components,
hydrogen and oxygen, under the arc. This hydrogen can then enter into the weld deposit and may lead to
unacceptable weld and heat affected zone cracking under certain conditions.
(3) The term “low hydrogen” was initially used to separate those SMAW electrodes capable of
depositing weld metal with low levels of diffusible hydrogen from non-low hydrogen electrodes such as
E6010 and E6012 that contain, by design, coating moisture levels of 2 to 4%. For prequalified WPSs,
AWS D1.1 Table 3.2 provides one series of minimum preheat and interpass temperatures for “non-low
hydrogen electrodes”, and another series of values for SMAW with low hydrogen electrodes and all
FCAW, SAW and GMAW. This implies a similarity in expected maximum levels of diffusible hydrogen.
C-1
CEMP-E
TI 809-26
1 March 2000
When SMAW low hydrogen electrodes are used, the required levels of preheat are lower, offering
economic and time-saving advantages to the contractor. AWS D1.1 and the AWS A5 filler metal
specifications do not currently define “low hydrogen.” International Institute of Welding (IIW) documents
classify electrodes for diffusible hydrogen as follows: very low hydrogen (0-5 mL / 100 g deposited weld
metal), low hydrogen (5-10), medium hydrogen (10-15), and high hydrogen (15-20), but these definitions
are unrelated to AWS usage and specifications.
EL
L
ED
(4) SMAW electrodes are classified based on a four or five digit number that follows the letter E
(for electrode). The electrode classification is imprinted on the coating near the end of the electrode, as
well as on the electrode package. See Table C-1. In filler metal specification AWS A5.1, low hydrogen
carbon steel SMAW electrodes are identified with the last “X” number in the designator EXXXX as a 5, 6
or 8. A5.1 SMAW low hydrogen electrode classifications include E7015, E7016, E7018, E7018M, E7028,
and E7048. The E7015 electrodes operate using DCEP only. E7016 electrodes operate using either AC
or DCEP. The E7018 electrodes operate using AC or DCEP, and include approximately 25% iron powder
in their coatings to increase their deposition rate. An E7028 electrode contains approximately 50% iron
powder in the coating, enabling it to deposit metal at even higher rates. However, as the nomenclature
shows, the “2" would indicate that this electrode is suitable for flat position welding and, for fillet welds
only, the horizontal position. E7018M electrodes may be used only with DCEP, and have been tested for
absorbed moisture and diffusible hydrogen. E7048 electrodes are similar to E7018 electrodes in
composition, and may be used in any position, AC or DCEP, except for vertical welding in the upward
progression. E7048 electrodes are specifically designed for good welding in the vertical downward
progression.
AN
C
(5) In the AWS A5.5 low-alloy steel SMAW electrode specification, a similar format is used to
identify SMAW electrodes. See Table C-2. The most significant difference in nomenclature from A5.1 is
the inclusion of a suffix letter and number indicating the alloy content. As an example, an E8018-C3
nickel steel electrode, with suffix “-C3", indicates the electrode nominally contains 1% nickel. A “-C1"
electrode nominally contains 2.5% nickel. Some electrodes carry the “-W” designation, indicating the
presence of alloys capable of giving the weld atmospheric corrosion resistance for exposed weathering
applications. Low hydrogen low-alloy SMAW electrodes are similarly identified with the last “X” number in
the designator EXXXX-Y as a 5, 6 or 8.
C
(6) Optional supplemental designators may be used to indicate the maximum level of hydrogen
that may be present in the test weld deposit. These designators are a part of the standard AWS
classification system and consist of the letter H followed by a single or double digit. For example “E7018H8" indicates that the deposit contains a maximum diffusible hydrogen content of 8 mL per 100 g of
deposited weld metal. Most standard low hydrogen electrodes must deposit weld metal with a maximum
of 16 mL per 100 g of diffusible hydrogen under test conditions. However, manufacturers may optionally
list an H8 or H4 designation if their particular SMAW electrodes are capable of delivering these extra low
levels of diffusible hydrogen.
(7) While “low-hydrogen” electrodes are required by AWS D1.1 for welding on structural steels with
minimum specified yield strength of 485 MPa (50 ksi) or greater, extra-low hydrogen levels should not be
specified unless necessary. There is generally a cost premium associated with the lower diffusible
hydrogen electrodes. Also, high notch toughness weld metal from electrodes with good operating
characteristics may not be available with the lowest hydrogen designations, and some electrodes with
very low diffusible hydrogen levels may have poor notch toughness.
(8) All low hydrogen electrodes listed in AWS A5.1 have minimum specified notch toughnesses of
27 J @ -20 oC (20 ft-lbf at 0°F) or better. See Table C-3 for specific data on these low hydrogen
C-2
CEMP-E
TI 809-26
1 March 2000
electrodes. There are electrode classifications that have no required notch toughness (such as E6012,
E6013, E6014, E7024), but these are not classified as low hydrogen electrodes. There is no direct
correlation between the low hydrogen limits of various electrodes and notch toughness requirements.
(9) Low hydrogen, low-alloy SMAW electrodes, up through 550 MPa (80 ksi), as listed with
operating limitations and uses in Table C-4. For electrodes exceeding 550 MPa (80 ksi), see AWS A5.5.
ED
(10) Electrodes providing a given level of notch toughness are listed in Table C-5. For the notch
toughness levels of higher strength electrodes, see AWS A5.5.
EL
L
(11) Low hydrogen SMAW electrodes typically are supplied in hermetically sealed metal
containers. When supplied in undamaged containers, they may be used without any preconditioning, or
baking, before use. When SMAW electrodes are received in damaged containers or in non-hermetically
sealed containers, AWS D1.1 requires that the electrodes be baked prior to use, in the range of 260 oC to
430oC (500 to 800°F), to remove any residual moisture picked up from exposure to the atmosphere. The
electrode manufacturer’s guidelines should be followed to ensure a baking procedure that eliminates
retained moisture, and these recommendations may vary from AWS D1.1 provisions.
(12) Once low hydrogen SMAW electrodes are removed from their hermetically sealed container,
or from the baking oven, they should be placed in a holding oven, also called a “rod oven” or “storage
oven”, to avoid the pickup of moisture from the atmosphere. These heated ovens must maintain the
electrodes at a minimum temperature of 120 oC (250°F). Once the electrode has been exposed to the
atmosphere, it begins to pick up moisture. AWS D1.1 Table 5.1 limits the exposure time of various
electrode classifications. Higher strength electrodes, used to join high strength steels which are
particularly susceptible to hydrogen assisted cracking, are limited to very short periods.
C
c. Advantages, Disadvantages and Limitations. Generally SMAW has a lower deposition rate and is
less efficient, and is more costly than the other structural welding processes of FCAW, GMAW and
SAW. SMAW is seldom used as the principal process for structural welding, but is commonly used for
tack welding, fabrication of miscellaneous components, and repair welding.
AN
(1) SMAW has the benefit of requiring relatively simple, inexpensive, portable, and easy to
maintain welding equipment. Gas shielding is not required. Holding ovens for low hydrogen electrodes
are required unless hermetically sealed containers are used to provide dry electrodes when needed.
SMAW is capable of depositing high quality welds, and is relatively tolerant of welding technique,
welding procedure variations, and wind. It can be used in areas with difficult access.
C
(2) Smaller prequalified weld bead sizes, maximum 8 mm (5/16 in.) in a single pass in the
common horizontal position, requires more passes for large welds, with additional cleaning time required
for slag removal. For long welds, because of the fixed length electrode, it may not be possible to
complete the weld without stopping, removing the slag to allow restarting the weld, and using additional
electrodes.
C-3
CEMP-E
TI 809-26
1 March 2000
Table C-1. AWS A5.1 Classification System for Carbon Steel Electrodes for SMAW
E XX YY M - 1 HZ R
Electrode
XX
Minimum tensile strength in units of 1 ksi (7 MPa)
60 = 60 ksi (420 MPa)
70 = 70 ksi (480 MPa)
Y
Generally, welding positions permitted for use, but may be additionally limited by
electrode diameter and class
1 = all positions (F, H, V, OH)
2 = F, H-fillets
4 = F, H, V-down, OH
Y
Type of covering
0 = high cellulose sodium (E6010)
0 = high iron oxide (E6020)
1 = high cellulose potassium
2 = high titania sodium
3 = high titania potassium
4 = iron powder, titania
5 = low hydrogen sodium
6 = low hydrogen potassium
7 = high iron oxide, iron powder
8 = low hydrogen potassium, iron powder (except E7018M)
9 = iron oxide titania potassium
M
If present, meets special Military specifications, and covering is low hydrogen, iron
powder
AN
-1
C
EL
L
ED
E
Optional supplemental diffusible hydrogen designator
H16 = maximum 16 mL / 100 g deposited weld metal
H8 = maximum 8 mL / 100 g deposited weld metal
H4 = maximum 4 mL / 100 g deposited weld metal
(note: E7018M meets H4 requirements, but the H4 designation is not used)
C
HZ
If present, indicates improved notch toughness (see AWS A5.1, Table 3)
for E7016-1, average CVN of 27 J @ -46oC ( 20 ft-lbf @ -50oF)
for E7018-1, average CVN of 27 J @ -46oC ( 20 ft-lbf @ -50oF)
for E7024-1, average CVN of 27 J @ -18oC ( 20 ft-lbf @ -0oF)
R
If present, indicates electrode has lower moisture content and meets absorbed
moisture test requirements
(note: E7018M must meet more stringent requirements, but the R designation is
not used)
C-4
CEMP-E
TI 809-26
1 March 2000
Table C-2. AWS A5.5 Classification System for Low-Alloy Steel Electrodes for SMAW
E XX YY M - X# HZ R
Electrode
XX
Minimum tensile strength in units of 1 ksi (7 MPa)
70 = 70 ksi (480 MPa)
80 = 80 ksi (550 MPa)
90 = 90 ksi (620 MPa)
100 = 100 ksi (690 MPa)
110 = 110 ksi (760 MPa)
120 = 120 ksi (830 MPa)
Y
Generally, welding positions permitted for use, but may be additionally limited by
electrode diameter and class
1 = all positions (F, H, V, OH)
2 = F, H-fillets
Y
Type of covering
0 = high cellulose sodium (except E7020)
0 = high iron oxide (E7020)
1 = high cellulose potassium
2 = high titania sodium
3 = high titania potassium
4 = iron powder, titania
5 = low hydrogen sodium
6 = low hydrogen potassium
7 = high iron oxide, iron powder
8 = low hydrogen potassium, iron powder (except EXX18M)
9 = iron oxide titania potassium
M
If present, meets special Military specifications, and covering is low hydrogen, iron
powder
Alloy
A
B
C
D
G
P
W
type
carbon-molybdenum steel
chromium-molybdenum steel
nickel steel
manganese-molybdenum steel
general low-alloy steel
for pipeline use
weathering steel
AN
X#
C
EL
L
ED
E
Optional supplemental diffusible hydrogen designator
H16 = maximum 16 mL / 100 g deposited weld metal
H8 = maximum 8 mL / 100 g deposited weld metal
H4 = maximum 4 mL / 100 g deposited weld metal
(note: EXX18M meets H4 requirements, but the H4 designation is not used)
C
HZ
R
If present, indicates electrode has lower moisture content and meets absorbed
moisture test requirements
C-5
CEMP-E
TI 809-26
1 March 2000
Table C-3. Low Hydrogen AWS A5.1 Carbon Steel Electrodes for SMAW
[to 480 MPa (70 ksi)]
Position
CVN
Toughness
Current
F, H, V, OH
DCEP
27 J @ -29oC
(20 ft-lbf @ 20oF)
0.6
H16, H8, H4
E7016
F, H, V, OH
AC, DCEP
27 J @ -29oC
(20 ft-lbf @ 20oF)
0.6
H16, H8, H4
E7018
F, H, V, OH
AC, DCEP
27 J @ -29oC
(20 ft-lbf @ 20oF)
0.6
H16, H8, H4
E7018M
F, H, V, OH
DCEP
68 J @ -29oC
(50 ft-lbf @ 20oF)
0.1
4.0
E7028
F, H-fillets
AC, DCEP
27 J @ -18oC
(20 ft-lbf @ 0oF)
0.3
H16, H8, H4
E7048
F, H, V-down,
OH
AC, DCEP
27 J @ -29oC
(20 ft-lbf @ 20oF)
0.4
H16, H8, H4
E7016-1
F, H, V, OH
AC, DCEP
27 J @ -46oC
(20 ft-lbf @ 50oF)
0.6
H16, H8, H4
E7018-1
F, H, V, OH
AC, DCEP
27 J @ -46oC
(20 ft-lbf @ 50oF)
0.6
H16, H8, H4
AN
C
EL
L
E7015
C
1
Available
Diffusible
Hydrogen
Limits
ED
Electro
de
Moisture
Content
Limit (as
received
)
- no H designation used for E7018M
C-6
1
CEMP-E
TI 809-26
1 March 2000
Table C-4. Low Hydrogen AWS A5.5 Low-Alloy Steel Electrodes for SMAW
[to 550 MPa (80 ksi)]
Position
Current
F, H, V, OH
DCEP
E7016-X
F, H, V, OH
AC, DCEP
E7018-X
F, H, V, OH
AC, DCEP
E8015-X
1
F, H, V, OH
DCEP
E8016-X
1
F, H, V, OH
AC, DCEP
E8018-X
1
F, H, V, OH
0.4
2
H16, H8, H4
0.4
2
H16, H8, H4
0.4
2
H16, H8, H4
0.2
H16, H8, H4
0.2
H16, H8, H4
EL
L
E7015-X
Available
Diffusible
Hydrogen
Limits
ED
Electrode
Moisture
Content Limit
(as received)
H16, H8, H4
AC, DCEP
0.2
- B3, B3L, B4L, B5, B6, B7, B7L, B8, B8L, and B9 series electrodes not prequalified
under AWS D1.1
2
- E70XX-XR and E70XX-X-HZR series Limit on Moisture Content (as received) = 0.3
1
CVN Toughness
Electrodes
E7018-W1
E8018-W2
AN
27 J @ -18oC
(20 ft-lbf @ 0oF)
C
Table C-5. Toughness Values for Low Hydrogen A5.5 Low Alloy Steel Electrodes
[to 550 MPa (80 ksi)]
E8016-C3, E8018-C3, E8018-NM1
27 J @ -51oC
(20 ft-lbf @ -60oF)
E7018-C3L
E8016-C4, E8016-D3, E8018-C4, E8018-D1, E8018-D3
27 J @ -60oC
(20 ft-lbf @ -75oF)
E8016-C1, E8018-C1
C
27 J @ -40oC
(20 ft-lbf @ -40oF)
27 J @ -73oC
(20 ft-lbf @ 100oF)
E7015-C1L, E7016-C1L, E7018-C2L
E8016-C2, E8018-C2
27 J @ -100oC
(20 ft-lbf @ 150oF)
E7015-C2L, E7016-C2L, E7018-C2L
C-7
CEMP-E
TI 809-26
1 March 2000
2. FLUX CORED ARC WELDING (FCAW).
ED
a. Process Principles. Flux cored arc welding (FCAW) is an arc welding process that uses a
continuous tubular electrode fed from a coil or spool into a welding “gun”. The electrode core contains
alloy additions, deoxidizers and flux materials. The heat of the arc causes the base metal, tubular
electrode wire and core materials to melt. The flux materials bind impurities, rise to the top of the molten
weld, and protect the cooling weld from atmospheric nitrogen or oxygen. Shielding of the exposed arc is
provided either by the decomposition of the core in self-shielded electrodes, designated FCAW-S, or by
an externally supplied gas or gas mixture, designated FCAW-G.
EL
L
(1) With FCAW-G, carbon dioxide (CO2) or a mixture of argon (Ar) of 75 to 90% and of CO 2 10 to
25% is used in addition to the gas provided by the flux core. The shielding gas selection may affect the
mechanical properties (yield and tensile strength, elongation, and notch toughness) of the weld. Carbon
dioxide, as a reactive gas, may cause some of the alloys in the electrode to become oxidized, and
therefore less alloy is transferred to the weld deposit. When an inert gas such as argon is substituted for
CO2, alloy transfer typically increases. With more alloy in the weld deposit, higher yield and tensile
strengths and reduced ductility is expected. The notch toughness of the weld deposit may increase or
decrease, depending on the alloys affected.
C
(2) The power source is usually the constant voltage type, using either direct current electrode
positive or electrode negative polarity. A separate wire feeder sends wire into the welding gun at a preset
rate. The Welding Procedure Specification (WPS) provides the appropriate voltage, wire feed speed,
electrode extension, and travel speed. For a given wire feed speed and electrode extension, a specific
current (amperage) will be provided. As the wire feed speed is increased, the current is likewise
increased. The WPS should, preferably, state the wire feed speed to be used because electrode
extension, polarity and electrode diameter also affect current. Shorter electrical stickout results in higher
current for a given wire feed speed. If current is used in the WPS, an inaccurate electrode extension may
go undetected.
AN
(3) FCAW is most commonly used as “semiautomatic”, wire fed but with the welding gun
manipulated by the welder. It may also be used as automatic, but the intensity of arc rays from the high
current arc, and the significant volume of smoke generated, make Submerged Arc Welding (SAW) more
desirable for automatic welding.
C
b. Filler Metal Designation, Specification and Certification. FCAW electrodes are specified in AWS
filler metal specifications AWS A5.20 and A5.29. AWS A5.20 is applicable to carbon steel electrodes,
and AWS A5.29 is applicable to low alloy steel electrodes. The classification and identification system
used for these two specifications is summarized in Tables C-6 and C-7.
(1) All FCAW electrodes are considered low hydrogen. Self-shielded FCAW electrodes are limited
to 550 MPa (80 ksi) tensile strength of less, but higher strengths are available from gas-shielded FCAW
electrodes. AWS A5.20 electrodes EXXT-2, -3, -10, -13, -14, and -GS electrodes are not permitted by
AWS D1.1 because they are limited to single pass welds. AWS A5.20 electrodes EXXT-3, EXXT-11, and
EXXT-14 are for limited thickness applications only, and the manufacturer’s recommendations should be
consulted.
(2) Tables C-8 and C-9 provide additional information regarding electrode limitations, usage and
toughness properties for electrodes permitted by AWS D1.1 for classification strengths of 550 MPa (80
ksi) and lower. For higher strength and other electrodes, the AWS A5.20 and A5.29 specifications should
be consulted.
C-8
CEMP-E
TI 809-26
1 March 2000
c. Advantages, Disadvantages and Limitations. The Flux Cored Arc Welding (FCAW) process offers
several advantages over Shielded Metal Arc Welding (SMAW), but also has a few disadvantages and
limitations
(1) The FCAW electrode is continuous, eliminating the numerous starts and stops necessary with
SMAW on longer and larger welds.
ED
(2) Increased deposition rates are possible with FCAW because the current can be higher than with
SMAW. SMAW currents are limited by rod heating and coating breakdown concerns. With FCAW, the
electrode is passed through a contact tip usually 20 to 25 mm (3/4 to 1 in.) from the end of the electrode,
minimizing the buildup of heat from electrical resistance. This electrode extension distance, commonly
called “stickout,” varies for each WPS, and may be considerably higher. Both factors provide FCAW an
economic advantage over SMAW.
(3) The number of arc starts and stops, a potential source of weld discontinuities, is also reduced.
EL
L
(4) The equipment required for FCAW is more expensive and complicated than SMAW, and more
difficult to maintain. This increased cost is offset by the higher productivity levels achieved using FCAW
compared to SMAW.
(5) FCAW electrode wires do not need heated holding ovens for ordinary applications, but caution
should be used when FCAW wires are exposed to the elements for extended periods of time. For critical
welds requiring very low hydrogen deposits, more restrictive storage requirements may be warranted.
C
(6) FCAW is capable of all-position welding when using small diameter electrodes. Large diameter
electrodes, using higher electrical currents, are restricted to the flat and horizontal positions.
AN
(7) There are several advantages to using FCAW-S (self-shielded) rather than FCAW-G (gasshielded). The FCAW-S welding gun assembly does not require a gas nozzle, also called a gas cup,
therefore access into smaller areas is possible, significant when welding in tight locations such as weld
access holes in beam-to-column connections. The welder is also better able to see the arc and weld
puddle because the gas cup is not present.
C
(8) A second advantage to FCAW-S over FCAW-G is its ability to make quality welds under field
conditions involving wind. For FCAW-G, it is necessary to erect protective shielding from wind to
maintain the shielding gas around the molten weld puddle. Such shielding may be expensive, timeconsuming, require additional ventilation for the welder, and constitute a fire hazard. FCAW-S eliminates
the handling of high pressure gas cylinders, theft of cylinders, protection of gas distribution hosing under
field conditions, and the cost of the shielding gas. For shop fabrication, wind is less of a problem than
under field conditions. However, drafts from doorways and windows, fans used to cool personnel and
provide ventilation, and welding fume exhaust equipment can create unacceptable wind speeds that
degrade weld quality.
(9) FCAW-G “operator appeal” is usually higher than with FCAW-S because of better arc control
and less fume generation. FCAW-G is less sensitive to variations in electrode extension and arc voltage
than FCAW-S. The range of suitable applications for a single size and classification of FCAW-G
electrodes is generally broader than for FCAW-S electrodes.
(10) FCAW-S procedures must be closely controlled to ensure the required level of weld quality
and mechanical properties. Because of the high deposition rates possible, travel speeds and technique
C-9
CEMP-E
TI 809-26
1 March 2000
C
AN
C
EL
L
ED
must be monitored to ensure that excessively large bead sizes are not produced. Large bead size,
because of the high heat input and excessively slow cooling rates, may reduce notch toughness, reduce
weld soundness, decrease heat affected zone toughness, and decrease the weld metal yield and tensile
strengths.
C-10
CEMP-E
TI 809-26
1 March 2000
Table C-6. AWS A5.20 Classification System for Carbon Steel Electrodes for FCAW
EXXT-XMJHZ
Electrode
X
Minimum Tensile Strength in units of 10 ksi (69 MPa)
6 = 60 ksi (420 MPa)
7 = 70 ksi (480 MPa)
X
Position of welding permitted
0 = flat and horizontal position only
1 = all positions
T
Tubular electrode
EL
L
-
ED
E
Type of electrode, numbered 1-14, or letter G or GS
M
If used, electrode has been classified using 75-80% Ar, with balance CO2
J
If used, electrode has toughness of 27 J @ -40oC (20 ft-lbf @ -40oF)
If not used, electrode has toughness as listed in A5.20, Table 1
HZ
Optional supplemental diffusible hydrogen designator
H16 = maximum 16 mL / 100 g deposited weld metal
H8 = maximum 8 mL / 100 g deposited weld metal
H4 = maximum 4 mL / 100 g deposited weld metal
C
AN
C
X
C-11
CEMP-E
TI 809-26
1 March 2000
Table C-7. AWS A5.29 Classification System for Low Alloy Steel Electrodes for FCAW
EXXTX-X#M
Electrode
X
Minimum Tensile Strength in units of 10 ksi (69 MPa)
6 = 60 ksi (420 MPa)
7 = 70 ksi (480 MPa)
8 = 80 ksi (550 MPa)
9 = 90 ksi (620 MPa)
10 = 100 ksi (690 MPa)
11 = 110 ksi (760 MPa)
12 = 120 ksi (830 MPa)
X
Position of welding permitted
0 = flat and horizontal position only
1 = all positions
T
Tubular electrode
X
Type of electrode, numbered 1, 4, 5, or 8
1 & 5 - gas-shielded
4 & 8 - self-shielded
C
type
carbon-molybdenum steel
chromium-molybdenum steel
nickel steel
manganese-molybdenum steel
other alloy steels
weathering steel
If used, electrode has been classified using 75-80% Ar, with balance CO2
C
M
Alloy
A
B
C
D
K
W
AN
X#
EL
L
-
ED
E
C-12
CEMP-E
TI 809-26
1 March 2000
Table C-8. AWS A5.20 Carbon Steel Electrodes for FCAW
[to 480 MPa (70 ksi), Multipass Only]
Electrode
Position
Testing Shielding
Gasd
F, H
CO
27 J @ -18oC
75-80% Ar - CO2
F, H, V-up, OH
75-80% Ar - CO
E70T-4
self
E70T-5
F, H
2
F, H
75-80% Ar - CO
CO2
E71T-5M
F, H, V-up, OH
F, H
E70T-7
DCEP
E70T-8
DCEP, DCEN
2
F, H
F, H
AN
E71T-9
E71T-9M
DCEP
2
75-80% Ar - CO
27 J @ -29 C
none specified
none specified
C
o
27 J @ -29 C
27 J @ -29o
DCEP
2
DCEP
C
27 J @ -29
o
b
F, H
self
none specified
b
F, H, V-dn, OH
self
none specified
F, H
CO
27 J @ -29oC
CO2
DCEP
EXa0T-G
not specified
not specified
C
E71T-12
EXa
27 J @ -29
27 J @ -290C
CO2
F, H, V-up, OH
C
o
DCEN
self
C
E70T-9
DCEP, DCEN
self
self
F, H, V-up, OH
27 J @ -29o
27 J @ -29oC
DCEN
F, H, V-up, OH
27 J @ -18o
DCEP
self
F, H
C
27 J @ -18oC
EL
L
E71T-5
DCEP
DCEP
2
F, H, V-up, OH
CVN Toughnessc
ED
E70T-1M
E71T-1
Current
F, H, V-up or V-dn,
not specified
C
not specified
o
Note - 27 J @ -18 C = 20 ft-lbf @ 0o
C = 20 ft-lbf @ -20 F
a
- May be either 6 or 7, for 60 ksi or 70 ksi tensile strength.
b
- electrodes with “J” at the end of the designator (e.g. E7XT-9J) have minimum CVN
Toughness of 27 J @ -40oC (20 ft-lbf @ -20o
CEMP-E
TI 809-26
1 March 2000
- Electrodes classified using the shielding gas listed shall not be used with any other
shielding gas mixture without first consulting the manufacturer.
C
AN
C
EL
L
ED
d
C-14
CEMP-E
TI 809-26
1 March 2000
Table C-9. AWS A5.29 Low Alloy Steel Electrodes for FCAW
[to 550 MPa (80 ksi), Multipass Only]
Electrode
Permitted
Positions
Testing
Shielding Gasd
Current
Minimum CVN Toughness
F, H, V, OH
self
DCEN
27 J @ -29oC (20 ft-lbf @ -20oF)
E70T4-K2
F, H
self
DCEP
27 J @ -18oC (20 ft-lbf @ 0oF)
E70T5-A1
F, H
CO2
DCEP
27 J @ -29oC (20 ft-lbf @ -20oF)
E71T8-K2
F, H
self
DCEN
27 J @ -29oC (20 ft-lbf @ -20oF)
E71T8-K6
F, H, V, OH
self
DCEN
27 J @ -29oC (20 ft-lbf @ -20oF)
E71T8-Ni1
F, H, V, OH
self
DCEN
27 J @ -29oC (20 ft-lbf @ -20oF)
E71T8-Ni2
F, H, V, OH
self
DCEN
27 J @ -29oC (20 ft-lbf @ -20oF)
E80T1-A1
F, H
E81T1-A1
F, H, V, OH
E80T1-B1
F, H
E81T1-B1
F, H, V, OH
E81T1-B2
F, H, V, OH
E80T1-B2H
F, H, V, OH
E80T1-K2
F, H
E80T1-Ni1
F, H
E81T1-Ni1
F, H, V, OH
EL
L
ED
E61T8-K6
DCEP
none specified
CO2
DCEP
none specified
CO2
DCEP
none specified
CO2
DCEP
none specified
CO2
DCEP
none specified
CO2
DCEP
none specified
CO2
DCEP
27 J @ -29oC (20 ft-lbf @ -20oF)
CO2
DCEP
27 J @ -29oC (20 ft-lbf @ -20oF)
CO2
DCEP
27 J @ -29oC (20 ft-lbf @ -20oF)
AN
C
CO2
F, H
CO2
DCEP
27 J @ -40oC (20 ft-lbf @ -40oF)
E81T1-Ni2
F, H, V, OH
CO2
DCEP
27 J @ -40oC (20 ft-lbf @ -40oF)
E80T1-W
F, H
CO2
DCEP
27 J @ -29oC (20 ft-lbf @ -20oF)
E80T5-B2
F, H
CO2
DCEP
none specified
E80T5-B2L
F, H
CO2
DCEP
none specified
C
E80T1-Ni2
E80T5-Ni1
F, H
CO2
DCEP
27 J @ -51oC (20 ft-lbf @ -60oF)
E80T5-Ni2
F, H
CO2
DCEP
27 J @ -60oC (20 ft-lbf @ -76oF)
E80T5-Ni3
F, H
CO2
DCEP
27 J @ -73oC (20 ft-lbf @ -100oF)
E80T5-K1
F, H
CO2
DCEP
27 J @ -40oC (20 ft-lbf @ -40oF)
E80T5-K2
F, H
CO2
DCEP
27 J @ -29oC (20 ft-lbf @ -20oF)
- Electrodes classified using the shielding gas listed shall not be used with any other
shielding gas mixture without first consulting the manufacturer.
d
C-15
CEMP-E
TI 809-26
1 March 2000
3. GAS METAL ARC WELDING (GMAW).
a. Process Principles. The Gas Metal Arc Welding (GMAW ) process, commonly referred to as “MIG”
(Metal Inert Gas) welding, is very similar to gas-shielded flux cored arc welding (FCAW-G), and uses the
same equipment. GMAW uses a solid or metal cored electrode, and subsequently leaves little, if any,
slag. The shielding gas used for GMAW may be carbon dioxide (CO 2), or a mixture of argon (Ar) and
either CO2 or small levels of oxygen (O), or both. GMAW is commonly applied in one of four ways: spray
arc transfer, globular transfer, pulsed arc transfer, and short arc transfer.
ED
(1) Spray arc transfer uses high wire feed speeds and relatively high voltages. A fine spray of
molten drops, all smaller in diameter than the electrode diameter, is ejected from the electrode toward
the work. The arc in spray transfer is continuously maintained, resulting in high quality welds with good
appearance. The shielding used for spray arc transfer is composed of at least 80% argon, with the
balance made up of either carbon dioxide or oxygen. Typical mixtures are 90% argon with 10% CO 2, and
95% argon with 5% oxygen. Because of the intensity of the arc, puddle fluidity, and lack of slag to hold
the molten metal in place, spray arc is limited to the flat and horizontal position.
EL
L
(2) Globular transfer results when high concentrations of carbon dioxide are used. Carbon dioxide,
as an active gas rather than inert gas, may be referred to as “MAG” (Metal Active Gas) welding. Because
of the high concentration of CO 2, the arc ejects large globular pieces of molten steel from the end of the
electrode, rather than a spray. This mode of transfer can result in deep penetration, but may have poor
appearance with relatively high levels of spatter. It is also limited to the flat and horizontal positions.
Because of the lower cost of CO 2 shielding gas, the lower level of heat generated, and increased welder
comfort, globular transfer may be selected in place of spray transfer.
AN
C
(3) Pulsed arc transfer uses a background current that is continuously applied to the electrode, plus
a pulsing peak current applied at a rate proportional to the wire feed speed. Each pulse of current ejects
a single droplet of metal from the electrode, usually between 100 and 400 times per second. The arc is
maintained by the lower background current. Pulsed arc transfer can be used out-of-position, with better
quality than short-circuiting mode. It is not as productive as spray transfer for welding in the flat and
horizontal positions. Weld appearance and quality are generally good. Pulsed arc transfer GMAW
equipment is somewhat more complex and costly than standard GMAW equipment.
C
(4) Short circuiting transfer, also called short arc, is suitable for welding only on thin gauge
materials, and should not be used for structural steel. The small diameter electrode is fed at a moderate
wire feed speed using relatively low voltage. The electrode contacts the workpiece, shorting the electrical
circuit, extinguishing the arc, resulting in very high current flowing through the electrode, causing it to
heat and melt. As the electrode melts, the arc is briefly reestablished. This cycle occurs up to 200 times
per second, creating a characteristic buzzing sound. With structural steel, significant fusion problems
such as cold lap may result. Short circuiting transfer provides a low deposition rate, but can be used out
of position. While GMAW is considered prequalified by AWS D1.1, the short circuiting mode of transfer,
abbreviated GMAW-S, is not. All GMAW-S welding procedures must be qualified by test.
b. Filler Metal Designation, Specification and Certification. GMAW electrodes are classified under
AWS A5.18 for carbon steel electrodes, and AWS A5.28 for low alloy steel electrodes. The classification
systems used for GMAW electrodes in AWS A5.18 and A5.28 are summarized in Tables C-10 and C-11.
(1) Classification testing is usually performed using specific welding procedures that use CO 2
shielding gas, therefore promoting globular transfer, but other gases, and therefore transfer modes, may
be specified.
C-16
CEMP-E
TI 809-26
1 March 2000
(2) Metal cored electrodes, previously classified as FCAW electrodes, are now listed in both A5.18
and A5.28. GMAW with metal cored electrodes is similar to FCAW, with a tubular electrode, but the core
contains metallic powders (alloy) rather than flux materials. Metal cored electrodes require less current to
obtain the same deposition rates, have better tolerance for mill scale and rust, and when used out-ofposition, are less likely to cold lap. Metal cored electrodes typically provide higher deposition rates
because higher currents may be used than with solid wire electrodes. Weld appearance is typically very
good, and the weld is essentially free of slag. The consistency of mechanical properties is typically better
with metal cored electrodes than with solid wire electrodes.
ED
(3) Properties and usage for GMAW electrodes, up to 550 MPa (80 ksi), are summarized in Tables
C-12 and C-13. For higher strength electrodes, see AWS A5.28.
c. Advantages, Disadvantages and Limitations. The Gas Metal Arc Welding (GMAW) process
offers several advantages over Shielded Metal Arc Welding (SMAW), but also has some disadvantages
and limitations.
EL
L
(1) The GMAW electrode is continuous, eliminating the numerous starts and stops necessary with
SMAW on longer and larger welds.
(2) Increased deposition rates are possible with GMAW because the current can be higher than
with SMAW. SMAW currents are limited by rod heating and coating breakdown concerns. With GMAW,
the electrode is passed through a contact tip usually 20 to 25 mm (3/4 to 1 in.) from the end of the
electrode, minimizing the buildup of heat from electrical resistance. This electrode extension distance,
commonly called “stickout,” varies for each WPS, and may be considerably higher. Both factors provide
GMAW an economic advantage over SMAW.
C
(3) The number of arc starts and stops, a potential source of weld discontinuities, is also reduced.
(4) GMAW electrode wires do not need heated holding ovens. For critical welds requiring very low
hydrogen deposits, GMAW electrode wires are available in the lowest diffusible hydrogen category, H2.
AN
(5) GMAW “operator appeal” is usually high because of good arc control and little fume generation.
(6) Because no flux is involved, GMAW is intolerant of high levels of mill scale, rust, and other
surface contaminants, and is limited to welding on relatively clean materials. Commonly, mill scale must
be removed by blast cleaning or power wire brushing prior to welding.
C
(7) GMAW is also seriously affected by wind because of the removal of the shielding gas from
around the weld puddle. For field work, it is often necessary to erect protective shielding from wind to
maintain the shielding gas around the molten weld puddle. Such shielding may be expensive, timeconsuming, require additional ventilation for the welder, and constitute a fire hazard. For shop
fabrication, wind is less of a problem than under field conditions. However, drafts from doorways and
windows, fans used to cool personnel and provide ventilation, and welding fume exhaust equipment can
create unacceptable wind speeds that degrade weld quality.
(8) The equipment required for GMAW is more expensive and complicated than SMAW, and more
difficult to maintain. This increased cost is offset by the higher productivity levels achieved using GMAW
compared to SMAW.
Table C-10. AWS A5.18 Classification System for Carbon Steel Electrodes for GMAW
C-17
CEMP-E
TI 809-26
1 March 2000
E XX C - X Y N HZ
E
If used, designates that electrode may also be used as filler rod
XX
Minimum Tensile Strength in units of 1 ksi (7 MPa)
S or C
S = Solid wire
X
EL
L
composite wire
G = unspecified composition
ED
R
Shielding gas used for classification testing
C = CO2
M = 75-80% Ar, balance CO2
N
applications
H16 = maximum 16 mL / 100 g deposited weld metal
H8 = maximum 8 mL / 100 g deposited weld metal
C
HZ
= maximum 2 mL / 100 g deposited weld metal
C
AN
H2
C-18
CEMP-E
TI 809-26
1 March 2000
Table C-11. AWS A5.28 Classification System for Low Alloy Steel Electrodes for
GMAW
ER XX S - XXX HZ
E XX C - XXX HZ
Electrode
R
If used, designates that electrode may also be used as filler rod
for GTAW
XX
Minimum Tensile Strength in units of 1 ksi (7 MPa)
70 = 70 ksi (480 MPa)
80 = 80 ksi (550 MPa)
90 = 90 ksi (620 MPa)
100 = 100 ksi (690 MPa)
110 = 110 ksi (760 MPa)
120 = 120 ksi (830 MPa)
S or C
S = Solid wire
C = Composite (metal cored) wire
EL
L
ED
E
-
Chemical composition of solid wire, or of weld deposit of
composite wire
A = carbon-molybdenum steel
B = chromium-molybdenum steel
Ni = nickel steel
D = manganese-molybdenum steel
1 = other alloy steels
G = not specified
HZ
Optional supplemental diffusible hydrogen designator
H16 = maximum 16 mL / 100 g deposited weld metal
H8 = maximum 8 mL / 100 g deposited weld metal
H4 = maximum 4 mL / 100 g deposited weld metal
H2 = maximum 2 mL / 100 g deposited weld metal
C
AN
C
XXX
C-19
CEMP-E
TI 809-26
1 March 2000
Table C-12. AWS A5.18 Carbon Steel Electrodes for GMAW
[480 MPa (70 ksi) only]
Polarity
CVN Toughness
ER70S-2
CO2
DCEP
27 J @ -29oC
(20 ft-lbf @ -20oF)
ER70S-3
CO2
DCEP
27 J @ -18oC
(20 ft-lbf @ 0oF)
ER70S-4
CO2
DCEP
not required
ER70S-5
CO2
DCEP
not required
ER70S-6
CO2
DCEP
27 J @ -29oC
(20 ft-lbf @ -20oF)
ER70S-G
E70C-3C
E70C-3M
E70C-6C
CO2
DCEP
as agreed
E70C-G(X)
27 J @ -29oC
(20 ft-lbf @ -20oF)
as agreed
CO2
DCEP
27 J @ -18oC
(20 ft-lbf @ 0oF)
75-80% Ar, balance
CO2
DCEP
27 J @ -18oC
(20 ft-lbf @ 0oF)
CO2
DCEP
27 J @ -29oC
(20 ft-lbf @ -20oF)
75-80% Ar, balance
CO2
DCEP
27 J @ -29oC
(20 ft-lbf @ -20oF)
AN
E70C-6M
EL
L
ER70S-7
ED
Testing Shielding
Gasd
C
Electrode
as agreed
as agreed
- Electrodes classified using the shielding gas listed shall not be used with any
other shielding gas mixture without first consulting the manufacturer.
d
C
Note - E70C-GS(X) electrode is limited to single pass applications, and is not
prequalified.
Note - All above electrodes optionally available as H16, H8, and H4 for diffusible
hydrogen requirements.
C-20
CEMP-E
TI 809-26
1 March 2000
Table C-13. AWS A5.28 Low Alloy Steel Electrodes for GMAW
[to 550 MPa (80 ksi), Multipass Only]
Polarity
CVN Toughness
ER70S-A1
Ar / 1-5% O2
DCEP
not required
ER70S-B2L
Ar / 1-5% O2
DCEP
not required
E70C-B2L
Ar / 1-5% O2
DCEP
not required
E70C-Ni2
Ar / 1-5% O2
DCEP
27 J @ -62oC
(20 ft-lbf @ -80oF)
ER80S-B2
Ar / 1-5% O2
DCEP
not required
ER80S-Ni1
Ar / 1-5% O2
DCEP
27 J @ -46oC
(20 ft-lbf @ -50oF)
ER80S-Ni2
Ar / 1-5% O2
DCEP
27 J @ -62oC
(20 ft-lbf @ -80oF)
ER80S-Ni3
Ar / 1-5% O2
DCEP
27 J @ -73oC
(20 ft-lbf @ -100oF)
ER80S-D2
CO2
DCEP
27 J @ -29oC
(20 ft-lbf @ -20oF)
Ar / 1-5% O2
DCEP
not required
Ar / 1-5% O2
DCEP
27 J @ -46oC
(20 ft-lbf @ -50oF)
E80C-Ni2
Ar / 1-5% O2
DCEP
27 J @ -62oC
(20 ft-lbf @ -80oF)
E80C-Ni3
Ar / 1-5% O2
DCEP
27 J @ -73oC
(20 ft-lbf @ -100oF)
EL
L
AN
E80C-Ni1
C
E80C-B2
ED
Testing Shielding
Gasd
Electrode
- Electrodes classified using the shielding gas listed shall not be used with any
other shielding gas mixture without first consulting the manufacturer.
C
d
Note - B3, B3L, B6, B8 and B9 classification electrodes are not prequalified
Note - All above electrodes optionally available as H16, H8, H4 and H2 for diffusible
hydrogen requirements.
C-21
CEMP-E
TI 809-26
1 March 2000
4. SUBMERGED ARC WELDING (SAW).
a. Process Principles. Submerged Arc Welding (SAW) uses a blanket of fusible granular material
called flux to shield the arc and molten metal. The arc is struck between the workpiece and a bare wire or
composite electrode, the tip of which is submerged in the flux. Since the arc is completely covered by
flux, it is not visible and the weld is made without the flash, spatter, sparks and smoke common for the
open-arc processes.
ED
(1) The process is typically operated automatic, or fully mechanized, although semiautomatic
operation is often used. The electrode is continuously fed from a coil or spool to the welding gun, which
travels at a preset speed along the joint, preceded by a flux deposition system. In semiautomatic
welding, the welder moves the gun, usually equipped with a flux-feeding device, along the joint by hand.
EL
L
(2) Flux feed may be by gravity flow through a nozzle from a small hopper atop the welding gun, or
it may be through a nozzle tube connected to an air-pressurized flux tank. Flux may also be applied in
advance of the welding operation, ahead of the arc, from a hopper run along the joint. Many fully
mechanized systems are equipped with vacuum devices to pick up the flux unfused after welding for
reuse.
C
(3) During welding, the heat of the arc melts some of the flux along with the steel and the tip of the
electrode. The tip of the electrode and the welding zone are always shielded by molten flux, surrounded
by a layer of unfused flux. As the electrode progresses along the joint, the lighter molten flux rises above
the molten metal in the form of a slag. The molten slag is a good conductor and provides an additional
path for the current, thus generating additional heat. The weld metal, having a higher melting (freezing)
point, solidifies while the slag above it is still molten. The slag then freezes over the newly solidified weld
metal, continuing to protect the metal from contamination while it is very hot and reactive with
atmospheric oxygen and nitrogen. Upon cooling and removal of any unmelted flux for reuse, the slag is
removed from the weld.
AN
(4) Several electrodes may be used in series or parallel, and multiple beads can be placed when
using separate power supplies for each bead. Parallel electrode SAW uses two electrodes connected
electrically in parallel to the same power supply. Both electrodes are fed by means of a single electrode
feeder. For heat input calculation purposes, the total for the two electrodes is used. Multiple electrode
SAW uses at least two separate power supplies and two separate wire drives to feed two electrodes
independently. To minimize the potential interaction of magnetic fields between the two electrodes,
typical SAW setups have the lead electrode operating on DC current while the trail electrode is operating
AC.
C
(5) DC and AC welding machines of both conventional drooping voltage type or constant potential
type can be used for SAW. With drooping voltage, a voltage sensitive relay adjusts the wire feed speed
to maintain the desired arc voltage. With constant potential voltage, the arc length is self-adjusting,
similar to the action in FCAW. Welding currents typically range from 500 to 1000 amperes.
(6) Flux must be stored so that it remains dry. Fluxes in open or damaged bags, or in flux hoppers,
may become contaminated with moisture from the atmosphere, so exposure should be limited. The
guidelines of the flux manufacturer, as well as AWS D1.1 Section 5.3.3 regarding storage and usage of
the flux must be followed. When not in use, flux hoppers should be covered or otherwise protected from
the atmosphere.
(7) Because unmelted flux does not undergo chemical changes, it may be recovered for future
use. Flux recovery systems range from vacuum recovery systems to sweeping with brooms and pans.
C-22
CEMP-E
TI 809-26
1 March 2000
Flux contamination through contact with oil, moisture, dirt, scale of other contaminants may occur,
therefore care is needed. Some loss of fine particulate matter may also occur with flux recovery,
therefore blending reclaimed flux with new flux is required.
ED
b. Filler Metal Designation, Specification and Certification. Submerged Arc Welding (SAW) filler
materials, the electrodes and fluxes, are classified under AWS A5.17 for carbon steel electrodes and
fluxes, and AWS A5.23 for low alloy steel electrodes and fluxes. Because SAW is dependent upon both
components, flux and electrode, the classification system integrates both materials. After an electrode
and flux combination is selected and a test plate welded, the flux-electrode classification may be
established. Specimens are extracted from the weld deposit to obtain the mechanical properties of the
flux-electrode combination, which must meet specific compositional and mechanical property
requirements.
EL
L
(1) The classification systems for SAW are summarized in Tables C-14 and C-15 for AWS A5.17
materials, and Table C-16 for AWS A5.23 materials. Low alloy steel SAW electrodes and fluxes
classified under AWS A5.23 have a more complex classification system, because of the variety of alloys
that may be involved, and because the composition of both the electrode and the resultant weld metal
must be specified.
(2) Because the submerged arc welding process is frequently used for pressure vessel fabrication
where assemblies are stress relieved, many submerged arc materials have been classified for the post
weld heat treated, or stress relieved, condition. When this is done, a “P” is placed in the designation
rather than an “A”. For structural work, which is seldom stress relieved, the “A” classification is commonly
used. Flux-electrode combinations classified in the post weld stress relieved condition may not exhibit
notch toughness when used in the as-welded condition, therefore investigation into weld metal properties
is warranted whenever the weld will be used differently than the filler metal classification condition.
C
(3) Fluxes are manufactured using one of four basic processes, and are further classified as
neutral, active or alloy fluxes, based upon their performance characteristics during welding.
C
AN
(4) Fused fluxes are made by blending deoxidizing and alloying ingredients, as necessary, and
then heating the mixture in a furnace until completely melted. A glass-like fused product is formed as the
liquid is cooled to ambient temperature, and later ground to the sizes required for welding. Fused fluxes
are nonhygroscopic, meaning they will not absorb water, but may be contaminated by moisture or other
products that adhere to the outside of particles. Fused fluxes are not subject to chemical segregation
during reuse because the complete composition is in each particle and cannot be separated. Fused
fluxes may have less than desired amounts of deoxidizer and ferro-alloy ingredients because of losses
that occur from the high temperatures during the manufacturing process. Fused flux performance can be
impeded by loss of fines during recycling. Fused fluxes with the required chemical composition generally
give the best low hydrogen welding performance.
(5) Bonded fluxes are made by combining all required chemical ingredients with a binder and
baking the product at low temperature to form hard granules, then broken up and screened for size.
Bonded fluxes contain chemically bonded moisture and can absorb moisture as well. Because the
product is baked at low temperature, deoxidizer content or alloying elements that can be added as ferroalloys or as elemental metals are not a problem as with fused fluxes. Bonded fluxes may segregate
during use and reuse, and gases may be produced in the molten slag during welding. Bonded fluxes tend
to break down during recycling and increase the percentage of fines.
(6) Agglomerated fluxes are similar to bonded fluxes in their method of manufacture, except that
the binder is a ceramic material that requires baking at higher temperatures. This may limit deoxidizer or
C-23
TI 809-26
ferro-alloy content due to high temperature losses. Agglomerated fluxes are generally considered
(7) Mechanically mixed fluxes can be a mixture of any flux type in any desired proportion, are
subject to segregation, and will have the attributes of their components.
ED
description and limitations of theses fluxes is provided in the Annexes to the AWS A5.17 and A5.23 filler
metal specifications.
manganese and silicon content, is relatively unaffected by changes in welding procedure variables,
primarily the voltage that determines arc length. For both active and alloy fluxes, the weld metal
EL
L
(10) Active fluxes have small additions of manganese and silicon, or both, to help offset the effects
of welding though mill scale and light coatings of rust. With active fluxes, a change in arc voltage will
are more resistant to porosity and cracking than welds made with neutral fluxes, active fluxes are often
used in making single pass fillet welds. Active fluxes intended for single pass fillet welding should not be
combine with the same elements in the electrode to produce weld metal with unacceptable properties.
The chemistry may build to unacceptable levels in larger multipass welds, therefore welding with active
C
with low levels of manganese and silicon. Where all mill scale and other contaminants are removed prior
to welding, the surface contamination tolerance of active fluxes is not needed. Continued recycling of
(11) Alloy fluxes contain alloys intended to improve the strength or corrosion resistance of the weld
metal, or both, and the composition of the weld metal is highly dependent upon the alloy content of the
AN
mechanical properties of the weld. Alloy fluxes, properly used with carbon steel electrodes, provide a
low-cost method of producing corrosion resistant weld metal for joining weathering steels. Unlike active
in the alloy content.
c. Advantages, Disadvantages and Limitations. Very high currents can be used in submerged arc
C
and deep penetration. The slag above the molten weld puddle acts as an insulating blanket,
concentrating heat in the welding zone and preventing rapid escape of heat. Deep penetration allows the
High travel speeds reduce the total heat input into the joint, reducing distortion.
(1) SAW welds generally have good ductility and toughness, and a uniform bead appearance
reducing cleaning and surface preparation costs. The covered arc allows SAW to be operated without the
need for extensive shielding to protect the operators from the high intensity arc created by the high
protection.
C-24
CEMP-E
TI 809-26
1 March 2000
C
AN
C
EL
L
ED
(2) The SAW process does not allow the operator to observe the molten weld puddle, forcing
reliance on the appearance of the slag blanket to indicate the quality of the weld bead. When SAW is
performed semi-automatically, the operator must acquire and practice a technique to produce good
welds without reliance upon arc and weld bead appearance.
C-25
CEMP-E
TI 809-26
1 March 2000
Table C-14. AWS A5.17 Classification System for Carbon Steel Electrodes and
Fluxes for SAW
[US Customary Units]
FSXXX-ECXXX-HZ
Flux (virgin flux if not followed by S)
S
Minimum tensile strength in units of 10 ksi (70 MPa)
7 = 70 ksi (480 MPa)
X
A = tested as-welded
P = tested after postweld heat treatment
ED
X
Electrode
C
EL
L
Temperature in F at or above the impact strength meets or exceeds 20 ft-lbf (27 J)
Z = no impact strength test required
0 = tested at 0o
C)
2 = tested at -20oF (-29o
F (-40oC)
5 = tested at -50o
C)
6 = tested at -60oF (-51o
F (-62oC)
C
specified in A5.17. ECG does not have a specified chemistry. Either type must be
tested with a specific flux.
AN
Manganese (Mn) content, % weight
L = low Mn (0.25 - 0.60)
H = high Mn (varies by classification, 1.30 low to 2.20 high)
G = chemistry not specified
Number that makes up a part of the electrode classification system, indicating
chemistry in A5.17, Table 1. Generally, indicates nominal carbon content in
C
nominal carbon), 11,12, 13, 14, and 15.
X
-
HZ
H16 = maximum 16 mL / 100 g deposited weld metal
H8 = maximum 8 mL / 100 g deposited weld metal
H2
= maximum 2 mL / 100 g deposited weld metal
C-26
CEMP-E
TI 809-26
1 March 2000
Table C-15. AWS A5.17 Classification System for Carbon Steel Electrodes and
Fluxes for SAW
[SI (Metric) Units]
FSXXX-ECXXX-HZ
Flux (virgin flux if not followed by S)
S
If present, flux is from crushed slag or blend of crushed slag and virgin flux.
X
Minimum tensile strength in units of 10 MPa (1.45 ksi)
43 = 430 MPa (62 ksi)
48 = 480 MPa (70 ksi)
X
Test condition of plates
A = tested as-welded
P = tested after postweld heat treatment
X
Temperature in oC at or above the impact strength meets or exceeds 27 J (20 ft-lbf)
Z = no impact requirements
0 = tested at 0oC ( 32oF)
2 = tested at -20oC ( -4oF)
3 = tested at -30oC (-22oF)
4 = tested at -40oC (-40oF)
5 = tested at -50oC (-58oF)
6 = tested at -60oC (-76oF)
EL
L
-
ED
F
Electrode
C
If present, electrode is Composite electrode. Electrode EC1 meets a chemistry
specified in A5.17. ECG does not have a specified chemistry. Either type must be
tested with a specific flux.
X
Manganese (Mn) content, % weight
L = low Mn (0.25 - 0.60)
M = medium Mn (varies by classification, 0.80 low to 1.50 high)
H = high Mn (varies by classification, 1.30 low to 2.20 high)
G = chemistry not specified
AN
Number that makes up a part of the electrode classification system, indicating
chemistry in A5.17, Table 1. Generally, indicates nominal carbon content in
hundredths of a percent. Listed classification numbers: 8 (indicating 0.08%
nominal carbon), 11,12, 13, 14, and 15.
C
X
C
E
X
-
K indicates that the electrode was made from silicon-killed steel.
CEMP-E
Optional supplemental diffusible hydrogen designator
H16 = maximum 16 mL / 100 g deposited weld metal
H8 = maximum 8 mL / 100 g deposited weld metal
H4 = maximum 4 mL / 100 g deposited weld metal
H2 = maximum 2 mL / 100 g deposited weld metal
C
AN
C
EL
L
ED
HZ
TI 809-26
1 March 2000
C-28
CEMP-E
TI 809-26
1 March 2000
Table C-16. AWS A5.23 Classification System for Low Alloy Steel Electrodes and
Fluxes for SAW
[US Customary Units]
F
Flux
9 = 90 ksi (620 MPa)
10 = 100 ksi (690 MPa)
Test condition of plates
A = tested as-welded
Temperature in o
Z = no impact strength test required
F ( -18oC)
2 = tested at -20o
C)
4 = tested at -40oF ( -40o
F ( -46oC)
6 = tested at -60o
C)
8 = tested at -80oF ( -62o
F ( -73oC)
o
15 = tested at -150
C)
EL
L
X
ED
Minimum tensile strength in units of 10 ksi (70 MPa)
7 = 70 ksi (480 MPa)
-
C
E
If present, electrode is Composite electrode with composition per AWS A5.23
X
Chemical composition of electrode (Table 1) or weld metal (Table 2)
AN
C
M = carbon steel, medium Mn solid electrode (EM12K)
A = carbon-molybdenum weld metal
1
Ni = nickel
C
M = military
W = weathering
XX
Number (and letter, if needed) that makes up a part of the electrode classification
N
Indicates that the electrode is intended for the core belt region of nuclear reactor
X
above
C-29
CEMP-E
N
Indicates that the weld metal is intended for the core belt region of nuclear reactor
vessels, with limited chemistry for phosphorous, vanadium, and copper.
HZ
Optional supplemental diffusible hydrogen designator
H16 = maximum 16 mL / 100 g deposited weld metal
H8 = maximum 8 mL / 100 g deposited weld metal
H4 = maximum 4 mL / 100 g deposited weld metal
- B3, B4, B5, B6, B6H, B8 are not prequalified in AWS D1.1
C
AN
C
EL
L
ED
1
TI 809-26
1 March 2000
C-30
TI 809-26
5.
a. Process Principles. Gas Tungsten Arc Welding (GTAW), also frequently called TIG (Tungsten
Inert Gas) welding, is done using the heat of an arc between a non-consumable tungsten electrode and
external shielding gas or gas mixture. Direct current electrode negative (DCEN) (straight) polarity is used
to produce a deep, narrow penetration when welding thicker materials. Direct current electrode positive
ED
metals. Alternating current (AC) is generally used for welding aluminum and magnesium alloys. A high
frequency oscillator is usually incorporated into GTAW power supplies to initiate the arc. This reduces
tungsten to the base metal. The process may be performed manually, but may also be used as
automatic. The tungsten electrode in the welding “torch” gets very hot under high duty cycles, therefore
EL
L
deposition rate through the use a continuous filler metal, supplied with current from a separate power
source, to preheat the wire using resistance heating.
welding torch are classified in AWS A5.12, Specification for Tungsten and Tungsten Alloy Electrodes for
. The filler metal used, if any, is rod classified for GMAW in AWS A5.18 or
A5.28, with a designation ER at the beginning. Tungsten electrodes are summarized in Table C-17.
spatter, with excellent arc control that is very beneficial for root passes. It can be used on material
thicknesses that range from thin sheet metals up to maximum of about 10 mm (3/8 in.). However,
C
AN
C
welding processes. Gas shielding is also critical, and wind speeds over 8 km per hour (5 mph) cause
quality and mechanical property degradation. GTAW, as an unfluxed welding process, also requires very
C-31
CEMP-E
TI 809-26
1 March 2000
Table C-17. AWS A5.12 Classification System for Tungsten Electrodes for GTAW
EWX-X
Electrode
W
Tungsten
X-X
Letter (and optionally -number) describing type of tungsten electrode
P = pure tungsten
Ce = tungsten-cesium alloy
La = tungsten-lanthanum alloy
Th = tungsten-thorium alloy
Zr = tungsten-zirconium alloy
G = general, not specified
C
AN
C
EL
L
ED
E
C-32
CEMP-E
TI 809-26
1 March 2000
a. Process Principles. Electroslag Welding (ESW) is used for welding thick sections, typically 50 mm
to 500 mm (2 to 20 in.) in thickness, for short to moderate lengths. The plates to be joined are positioned
40 mm (3/4 to 1-1/2 in.), depending on welding equipment and material thickness, with no edge
preparation generally required. Water-cooled copper shoes are placed on each side of the joint, forming
ED
used. Shielding of the arc and weld pool is provided by the addition of flux into the joint as welding
progresses. To start the weld, an arc is struck in a sump at the bottom of the joint, underneath a deposit
The arc is extinguished by the slag, but the fed electrode wire and adjacent base metal melts from the
heat generated by the high electrical resistance of the slag. The weld proceeds as more electrode is fed
EL
L
weld termination. Both the starting sump and finishing run-off tab are removed after completion of
welding.
specified in AWS A5.25, Specification for Carbon and Low-Alloy Steel Electrodes and Fluxes for
. Electrode wires may be either solid or composite. The classification system is
summarized in Table C-18.
deposition rates, in the range of 20 kg (40 lb.) per hour, offering considerable cost and time savings for
vertical welding of thick steels. Time and expense is also saved in the avoidance of joint preparation,
C
distortion upon completion.
(1) ESW, if interrupted during welding, can leave major discontinuities in the joint that are difficult
AN
may cause low toughness properties, as well as make ultrasonic testing more difficult.
(2) ESW can be used for joints over 12 mm (1/2 in.) thick, but generally does not become the most
C
including the number of joints to be welded. ESW is not prequalified under AWS D1.1
qualification testing following AWS D1.1
vertical require special setups and procedures, although ESW has been performed at angles to 45
degrees.
C-33
CEMP-E
TI 809-26
1 March 2000
Table C-18. AWS A5.25 Classification System for Electrodes and Fluxes for ESW
FESXX-XXX
Flux for Electroslag Welding
X
Minimum tensile strength in units of 10 ksi (70 MPa)
6 = 60 ksi (420 MPa)
7 = 70 ksi (480 MPa)
X
Temperature in oF at or above the impact strength meets or exceeds 15
ft-lbf (20 J)
Z = no impact strength test required
0 = tested at 0oF (-18oC)
2 = tested at -20oF (-29oC)
ED
FES
-
Electrode classification used (EM5K-EW, for example), see AWS A5.25
C
AN
C
EL
L
XXX
C-34
TI 809-26
7.
a. Process Principles. Electrogas Welding (EGW) is very similar to Electroslag Welding (ESW), and
is used for welding thick sections, typically 50 mm to 500 mm (2 to 20 in.) in thickness, for short to
opening gap at the joint is generally set to approximately 22 mm (7/8 in.), depending on welding
equipment and material thickness, with no edge preparation generally required. Water-cooled copper
ED
current electrode negative (DCEN) currents of 500 to 700 amperes are commonly used. The electrode is
either a solid wire, composite (cored) wire, or a flux cored wire designed for EGW. For solid wires,
or an argon-CO 2 mix.
When flux cored wires are used, the shielding gas may or may not be necessary, depending upon the
weld pool and allows the welding arc to stabilize before reaching the actual joint. The arc is maintained,
and the fed electrode wire and adjacent base metal melts from the heat generated by the arc. The weld
EL
L
Both the starting sump and finishing run-off tab are removed after completion of welding.
b. Filler Metal Designation, Specification and Certification. Filler materials, electrodes and fluxes
Specification for Carbon and Low-Alloy Steel Electrodes and
Electrogas Welding
classification system is summarized in Table C-19.
c. Advantages, Disadvantages and Limitations. Electrogas Welding (EGW) provides very high
C
vertical welding of thick steels. Time and expense is also saved in the avoidance of joint preparation,
preheating and interpass temperature control, and interpass cleaning. The joint is also free from angular
AN
(1) EGW, if interrupted during welding, can leave major discontinuities in the joint that are difficult
to access and repair. The large grain size from the substantial heat input, and subsequent slow cooling,
disadvantage, compared to ESW, of requiring protection of the joint from wind over 8 km per hour (5
mph).
C
economical choice until a thickness of around 50 mm (2 in.) is welded, depending upon several factors
including the number of joints to be welded. EGW is not prequalified under AWS
, therefore
qualification testing following AWS
Section 4 is required. Angles beyond 10 to 15 degrees from
vertical may require special setups and procedures.
C-1 March 200035
CEMP-E
TI 809-26
1 March 2000
Table C-19. AWS A5.26 Classification System for Electrodes for EGW
EGXXX-XXX
Electrogas Welding
X
Minimum tensile strength in units of 10 ksi (70 MPa)
6 = 60 ksi (420 MPa)
7 = 70 ksi (480 MPa)
8 = 80 ksi (550 MPa)
X
Temperature in oF at or above the impact strength meets or exceeds 20 ft-lbf (27 J)
Z = no impact strength test required
0 = tested at 0 oF (-18oC)
2 = tested at -20 oF (-29oC)
X
S = solid wire
T = tubular wire
Electrode classification used, see AWS A5.26
C
AN
C
XXX
EL
L
-
ED
EG
C-36
TI 809-26
APPENDIX D
1. VISUAL TESTING (VT).
a. Method Description. Visual inspection, as a form of nondestructive testing, is the visual observation
ED
the first nondestructive testing method applied, and if the inspected item fails to meet visual criteria,
more extensive nondestructive testing should not be conducted until the visual criteria is satisfied.
and other enhancements. Such instruments tend to distort the perception of the inspector. When surface
discontinuities such as cracks are suspected, the use of magnifying devices to further investigate the
such as weld gauges are required.
EL
L
(2) Visual inspection includes the measurement of the work, which may include the smoothness of
thermally cut edges, and the measurement of root openings, groove angles, weld size, convexity and
b. Advantages and Disadvantages.
C
arc strikes, excessive convexity, overlap, toe cracks, undersized welds, undercut, seams and laminations
at exposed edges. Not all listed discontinuities are structurally significant, but they may provide indication
AN
(2) Visual inspection cannot reveal subsurface discontinuities such as cracks, incomplete fusion,
slag inclusions, incomplete penetration, buried laminations or lamellar tearing. See Table D-1.
surrounding heat-affected zone (HAZ).
(4) The cost of visual inspection is usually less, per unit length of weld, that the other methods of
C
rather than simple verification measurements and recording of unsatisfactory workmanship.
D-1
CEMP-E
TI 809-26
1 March 2000
Table D-1. Visual Inspection
Most Applicable
Lap, < 6 mm (< 0.2 in.)
Lap, 6-15 mm (0.2 - 0.6 in.)
Both-Side Access
Double-V Groove
Longitudinal Cracks
Transverse Cracks
Radiating Cracks
Uniform Porosity
Linear Porosity
Elongated Cavity
“Worm Hole”
Incomplete Fusion
(Sidewall or Interpass)
Incomplete Fusion (Root)
ED
Crater Cracks
Group Discontinuous
Cracks
Branching Cracks
Surface Pore
Crater Pipe
Incomplete Penetration
Overlap
C
AN
C
Joint
Geometry
Microcracks
Shrinkage Cavity
Undercut
Excessive
Reinforcement
Excessive Convexity
Excessive Penetration
Misalignment
Burn-Through
Underfilled Groove
Irregular Bead
Root Concavity
Poor Restart
Miscellaneous Surface
Discontinuities
(Spatter, etc.)
Least Applicable
EL
L
D
i
s
c
o
n
t
i
n
u
i
t
y
Applicable
D-2
Lap, 16 - 50 mm (0.6 - 2 in.)
Lap, > 50 mm (> 2 in.)
One-Side Only Access
Single-V Groove
CEMP-E
TI 809-26
1 March 2000
2. PENETRANT TESTING (PT).
ED
a. Method Description. Penetrant testing, also called dye penetrant or liquid penetrant testing, is the
use of a liquid penetrating dye to detect discontinuities at the surface of a weld or base metal. The
penetrant is applied to the surface, allowed to remain on the surface for a specified dwell time to
penetrate cracks, pores, or other surface-breaking discontinuities, and then is carefully removed. A
developer is then applied to the surface, which draws the penetrant out of the discontinuities. This leaves
a visible contrasting indication in the developer, which is then removed for closer visual examination of
the area providing indications. One method of penetrant testing uses a visible dye, usually red, which
contrasts with the developer, usually white. The second method uses a flourescent dye, visible under
ultraviolet light. Flourescent methods are usually more sensitive, but require a darkened area for testing.
b. Advantages and Disadvantages.
(1) Penetrant testing is relatively economical compared to ultrasonic testing, and especially
economical when compared to radiographic testing.
EL
L
(2) Testing materials are small, portable, and inexpensive, with no specialized equipment required
unless an ultraviolet light is used.
(3) A relatively short period of training is necessary for technicians who will be performing PT.
(4) PT can be performed relatively quickly, depending upon the penetrant used and the required
dwell time.
C
(4) A disadvantage with some penetrants and developers is the safe handling and disposal of used
liquids and cleaning rags.
(5) Cleaning after inspection to remove residual penetrant and developer prior to weld repairs or
the application of coating systems can sometime be difficult and time-consuming.
AN
(6) Rough surface conditions, and irregular profile conditions such as undercut and overlap, can
sometimes provide false indications of weld toe cracks when cleaning is not thoroughly performed. Weld
spatter can also make surface removal of the penetrant more difficult.
(7) PT cannot be performed when the surface remains hot, unless special high-temperature PT
materials are used, so waiting time is sometimes necessary with PT that would not be required with
magnetic particle testing.
C
(8) Existing coatings should be removed prior to PT because the coating may bridge narrow
cracks, preventing the entry of the penetrant.
(9) PT is especially effective with small surface-breaking cracks, such as toe cracks, and also
surface-breaking piping porosity, crater cracks, laminations along exposed edges and joint preparations,
and other surface discontinuities.
(10 PT is ineffective for any discontinuity below the surface, such as buried cracks, slag inclusions,
lack of fusion, or incomplete penetration. See Table D-2.
D-3
CEMP-E
TI 809-26
1 March 2000
Table D-2. Penetrant Testing
Radiating Cracks
Surface Pore\
Crater Pipe
Overlap
Miscellaneous Surface
Discontinuities
(Spatter, etc.)
Longitudinal Cracks
Transverse Cracks
Crater Cracks
Group Discontinuous Cracks
Branching Cracks
Uniform Porosity
Linear Porosity
Shinkage Cavity
Incomplete Fusion
(Sidewall or Interpass)
Incomplete Fusion (Root)
Incomplete Penetration
Undercut
Burn-Through
Microcracks
Elongated Cavity
“Worm Hole”
Lap, < 6 mm (< 0.2 in.)
Lap, 6-15 mm (0.2 - 0.6 in.)
Both-Side Access
Double-V Groove
Lap, 16 - 50 mm (0.6 - 2 in.)
Lap, > 50 mm (> 2 in.)
One-Side Only Access
Single-V Groove
C
AN
C
Joint
Geometry
Least Applicable
EL
L
D
i
s
c
o
n
t
i
n
u
i
t
y
Applicable
ED
Most Applicable
D-4
CEMP-E
TI 809-26
1 March 2000
3. MAGNETIC PARTICLE TESTING (MT).
ED
a. Method Description. Magnetic particle testing uses the relationship between electricity and
magnetism to induce magnetic fields in the steel. Magnetic particles, commonly in the form of iron
powder colored for better visibility, are dusted onto the magnetized surface. Cracks and other
discontinuities on or near the surface disturb the lines of magnetic force, essentially acting as poles of a
magnet, attracting the magnetic particles. After the area has been magnetized, the particles are applied,
then removed with gentle dusting or application of air. Particles attracted to discontinuities remain on the
surface at the discontinuity, attracted to the magnetic poles. The MT technician then evaluates the
location and nature of the indicating particles. Tight lines are indicative of surface cracks or other
discontinuities. Subsurface cracks and slag inclusions would show a broader indication. A permanent
record of detected discontinuities can be made with the use of transparent adhesive tape or photography.
(1) The magnetic fields can be induced using either prods, which directly magnetize the steel
through direct contact with the steel and the induction of current flow in the steel, or with a yoke, which
does not transfer electrical current but provides magnetic flux between the two elements of the yoke.
EL
L
(2) MT equipment may be operated either DC (rectified AC) or AC. DC provides higher
magnetization levels which allows for inspection for discontinuities somewhat below the surface.
Inspection with AC is generally limited to surface-breaking and very near-surface discontinuities, and is
considered more effective for surface discontinuities because the particles are more mobile.
b. Advantages and Disadvantages.
(1) MT is relatively fast and economical.
C
(2) The equipment is relatively inexpensive, compared with ultrasonic or radiographic equipment.
(3) A source of electric power is necessary.
AN
(4) Inspection costs are generally equal to or slightly more than PT, but considerably less than UT
or RT.
(5) More training is necessary for MT, compared to PT, but substantially less than that required for
UT or RT.
(6) MT can be performed effectively while the joint is still warm from welding or postheating.
C
(7) After inspection, removal of magnetic particles is quick and thorough, not delaying repairs or
affecting coating application.
(8) Existing coatings may reduce the effectiveness of MT.
(9)The depth of inspectability depends upon the equipment, selection of current, and the type of
particles used. Although opinions vary as to the maximum depth that can be effectively inspected using
MT, 8 mm (5/16 in.) is generally considered the deepest discontinuity that can be detected under good
conditions.
(10) MT is effective for detecting surface-breaking discontinuities such as cracks and laminations.
It is also effective for cracks, laminations, incomplete fusion, slag inclusions, and incomplete penetration
D-5
CEMP-E
TI 809-26
1 March 2000
if slightly below the surface. Rounded discontinuities such as porosity do not disturb the magnetic flux
lines sufficiently to be effectively detected. See Table D-3.
Table D-3. Magnetic Particle Testing
Most Applicable
Longitudinal Cracks
Transverse Cracks
Radiating Cracks
Crater Cracks
Group Discontinuous Cracks
Branching Cracks
Surface Pore
Shrinkage Cavity
Crater Pipe
Incomplete Fusion
(Sidewall or Interpass)
Incomplete Fusion (Root)
Incomplete Penetration
Undercut
Overlap
Microcracks
Uniform Porosity
Linear Porosity
Elongated Cavity
“Worm Hole”
Burn-Through
Miscellaneous Surface
Discontinuities
(Spatter, etc.)
Lap, 6-15 mm (0.2 - 0.6 in.)
Both-Side Access
Double-V Groove
Lap, 16 - 50 mm (0.6 - 2 in.)
Lap, > 50 mm (> 2 in.)
One-Side Only Access
Single-V Groove
EL
L
Lap, < 6 mm (< 0.2 in.)
C
AN
C
Joint
Geometry
Least Applicable
ED
D
i
s
c
o
n
t
i
n
u
i
t
y
Applicable
D-6
CEMP-E
TI 809-26
1 March 2000
4. ULTRASONIC TESTING (UT).
ED
a. Method Description. Ultrasonic testing requires specialized equipment to produce and receive
precise ultrasonic waves induced into the steel using piezoelectric materials. The unit sends electric
pulses into the piezoelectric crystal, which converts electrical energy into vibration energy. The vibration
is transmitted into the steel from the transducer using a liquid couplant. The vibration is introduced into
the steel at a known angle, depending upon the design of the transducer, with a known frequency and
waveform. The speed of travel of the vibration in steel is also known. The vibration pulse travels through
the steel until it strikes a discontinuity, or the opposite face of the steel, either of which reflects energy
back to the transducer unit or another receiving transducer. Using a system of calibration and
measurements, the location, relative size and nature of the discontinuity, if any, can be determined by
close evaluation of the reflected signals. Small reflections are generally ignored, unless located in
specific regions such as along edges. Locations of discontinuities can be determined using the display
screen scale and simple geometry.
EL
L
(1) AWS D1.1 Section 6, Part F provides the UT inspection procedures, including calibration,
scanning methods, scanning faces, and transducer angles, and weld acceptance criteria, including
reflected signal strength, discontinuity lengths and locations for weld discontinuities. Report forms,
generally hand written, are prepared by the UT technician, recording weld discontinuities and other
material discontinuities that exceed the acceptance criteria specified.
C
(2) More expensive and sophisticated UT equipment can be operated in digital mode, recording
and printing display screen images with input data. Very sophisticated automated UT equipment can
record the transducer location and the corresponding reflections, then use computer software systems to
produce representative two-dimensional images, from various directions, of the inspected area and
discontinuities. Such equipment is rarely used in normal construction inspection applications, but is
available and sometimes used for very complex and critical inspections.
AN
(3) Even with conventional equipment, more complex inspection methods can be used to locate,
evaluate and size weld discontinuities. These techniques include tip diffraction and time-of-flight
techniques, and can be incorporated into project inspection through the use of AWS D1.1 Annex K
provisions. Annex K requires the use of written UT procedures specific to the application, with
experienced and qualified UT technicians tested in the use of the procedures, and also provides for
alternate acceptance criteria in lieu of the tables found in Section 6, Part F of AWS D1.1. Such
provisions are necessary when using miniature transducers, alternate frequencies, or scanning angles
other than those prescribed.
b. Advantages and Disadvantages.
C
(1) Ultrasonic testing is a highly sensitive method of NDT, and is capable of detecting discontinuity
in welds and base metal in a wide variety of joint applications and thicknesses.
(2) AWS D1.1 provisions are applicable for thickness ranges from 8 mm (5/16 in.) to 200 mm (8
in.) Both thinner and thicker materials may be examined and evaluated using UT, but Annex K must be
used for technique and acceptance.
(3) Although capable of locating discontinuities and measuring discontinuity length, it is less
capable of directly sizing discontinuities or determining discontinuity height without the use of advanced
techniques.
D-7
CEMP-E
TI 809-26
1 March 2000
(4) A primary disadvantage of ultrasonic testing is that it is highly dependent upon the skill of the
UT technician.
(6) The cost of the equipment is considerably more that MT, but also much less than RT. The cost
of more sophisticated UT units capable of computer-generated imaging approaches, and sometimes
exceeds, the cost of RT equipment.
ED
(7) UT indications are difficult to interpret in certain geometric applications. It is ineffective for fillet
welds unless very large, and then only for the root area for fillet welds above approximately 18 mm (3/4
in.). When backing bars remain in place, it is difficult to distinguish between the backing bar interface
and cracks, slag lines, or lack of penetration or fusion at the root. With partial joint penetration groove
welds, it is difficult to distinguish between the unfused root face and discontinuities near the root. In
welded beam-to-column moment connections, the interference of the web with inspection of the bottom
flange makes direct evaluation of the area beneath the weld access hole difficult. Second-leg
inspections, not as accurate or as reliable as first-leg inspections, are necessary to evaluate the entire
depth of many welds unless the weld face is ground flush. Discontinuities located just below the weld or
material surface are also difficult to detect.
EL
L
(8) UT is best suited for planar discontinuities such as cracks and lack of fusion, discontinuities
which are generally most detrimental to joint performance when oriented transverse to the direction of
loading. These discontinuities tend to be irregular with rough surfaces, and therefore reflect signals even
when not exactly perpendicular to the direction of the pulse. Laminations and lamellar tears are also
easily detected. Smooth surfaces, such as unfused root faces, would redirect a signal and provide a
weak response unless oriented perpendicular to the pulse. Rounded and cylindrical discontinuities such
as porosity disperse the signal, also providing a weak response, but such rounded discontinuities are
rarely detrimental to joint performance. Slag inclusions are irregular and provide easily identifiable
responses. See Table D-4.
C
AN
C
(9) The cost of ultrasonic testing is considerably more than PT or MT, and considerably less than
RT. However, UT is the best method for detection of the most serious weld discontinuties in a wide
variety of thicknesses and joints. The time, and therefore cost, of UT inspection can vary greatly,
depending upon the quality of the weld to be inspected. A good quality weld will provide few responses,
requiring little evaluation time. A difficult configuration, or a poor quality weld, will require numerous
time-consuming evaluations and recording of test data.
D-8
CEMP-E
TI 809-26
1 March 2000
Table D-4. Ultrasonic Testing
Most Applicable
Microcracks
Crater Cracks
Group Discontinuous Cracks
Branching Cracks
Uniform Porosity
Linear Porosity
“Worm Hole”
Surface Pore
Shrinkage Cavity
Crater Pipe
Undercut
Excessive Reinforcement
Excessive Convexity
Excessive Penetration
Overlap
Misalignment
Underfilled Groove
Root Concavity
ED
Lap, < 6 mm (< 0.2 in.)
Lap, 6-15 mm (0.2 - 0.6 in.)
Both-Side Access
Double-V Groove
C
AN
C
Joint
Geometry
Transverse Cracks
Radiating Cracks
Elongated Cavity
Solid Inclusion
Slag or Flux Inclusion
Oxide Inclusion
Metallic Inclusion
Incomplete Fusion (Root)
Incomplete Penetration
Burn-Through
Irregular Bead
Poor Restart
Least Applicable
EL
L
D
i
s
c
o
n
t
i
n
u
i
t
y
Longitudinal Cracks
Incomplete Fusion
(Sidewall or Interpass)
Applicable
D-9
Lap, 16 - 50 mm (0.6 - 2 in.)
Lap, > 50 mm (> 2 in.)
One-Side Only Access
Single-V Groove
CEMP-E
TI 809-26
1 March 2000
5. RADIOGRAPHIC TESTING (RT).
ED
a. Method Description. Radiographic Testing (RT) uses a radioactive source and, typically, a film
imaging process similar to X-ray film. The film provides a permanent record of the inspection. When a
weld is exposed to penetrating radiation, some radiation is absorbed, some scattered, and some
transmitted through the weld onto the film. Image Quality Indicators (IQIs) are used to verify the quality
and sensitivity of the image. Most conventional RT techniques involve exposures that record a
permanent image on film, although other image recording methods are also used. Real-time radiography
uses a fluoroscope to receive radiation, then presents an on-screen image for evaluation. The two types
of radiation sources commonly used in weld inspection are x-ray machines and radioactive isotopes.
(1) X-rays are produced by portable units capable of radiographing relatively thin objects. A large
2000 kV X-ray unit is capable of penetrating approximately 200 mm (8 in.) of steel, a 400 kV unit to 75
mm (3 in.), and a 200 kV unit to 25 mm (1 in.) of steel.
EL
L
(2) Radioisotopes are used to emit gamma radiation. The three most common RT isotopes are
cobalt 60, cesium 137, and iridium 192. Cobalt 60 can effectively penetrate up to approximately 230 mm
(9 in.) of steel, cesium 137 to 100 mm (4 in.), and iridium 192 to 75 mm (3 in.) of steel.
b. Advantages and Disadvantages.
(1) RT can detect subsurface porosity, slag, voids, cracks, irregularities, and lack of fusion. See
Table D-5.
(2) Accessibility to both sides of the weld is required.
C
(3) RT is limited to butt joint applications by AWS D1.1. Because of the constantly changing
thickness for the exposure, RT is not effective when testing fillet welds or groove welds in tee or corner
joints.
AN
(4) To be detected, an imperfection must be oriented roughly parallel to the radiation beam. As a
consequence, RT may miss laminations and cracks parallel to the film surface. Because they are usually
volumetric in cross-section, discontinuities such as porosity or slag are readily detected.
(5) The limitations on RT sensitivity are such that discontinuities smaller than about 1½ percent of
the metal thickness may not be detected.
C
(6) The radiographic images provide a permanent record for future review, and aid in
characterizing and locating discontinuities for repair.
(7) RT is generally unaffected by grain structure, particularly helpful with ESW and EGW welds.
(8) RT is a potential radiation hazard to personnel, and strict safety regulations must be monitored
and enforced.
(9) The cost of radiographic equipment, facilities, safety programs, and related licensing is higher
than any other NDT process.
(10) There is usually a significant waiting time between the testing process and the availability of
results.
D-10
CEMP-E
TI 809-26
1 March 2000
Table D-5. Radiographic Testing
Most Applicable
Lap, 6-15 mm (0.2 - 0.6 in.)
Both-Side Access
Double-V Groove
Lap, < 6 mm (< 0.2 in.)
Lap, 16 - 50 mm (0.6 - 2 in.)
Lap, > 50 mm (> 2 in.)
Single-V Groove
Least Applicable
Microcracks
Overlap
ED
Surface Pore
Shrinkage Cavity
Crater Pipe
Incomplete Fusion
(Sidewall or Interpass)
Undercut
Excessive Reinforcement
Excessive Convexity
Excessive Penetration
Burn-Through
Underfilled Groove
Root Concavity
Miscellaneous Surface
Discontinuities (Spatter, etc.)
C
AN
C
Joint
Geometry
Longitudinal Cracks
Transverse Cracks
Radiating Cracks
Crater Cracks
Group Discontinuous
Cracks
Branching Cracks
Uniform Porosity
Linear Porosity
Elongated Cavity
“Worm Hole”
Solid Inclusion
Slag or Flux Inclusion
Oxide Inclusion
Metallic Inclusion
Incomplete Fusion (Root)
Incomplete Penetration
EL
L
D
i
s
c
o
n
t
i
n
u
i
t
y
Applicable
D-11
CEMP-E
TI 809-26
1 March 2000
6. OTHER METHODS.
C
AN
C
EL
L
ED
Because of severe limitations in applicability, the use of eddy current, acoustic emission, or other
methods not mentioned above is discouraged.
D-12
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertisement