AWS G2.3M/G2.3:2019

An American National Standard

Guide for the Joining of Solid Solution Austenitic Stainless Steels

AWS G2.3M/G2.3:2019

An American National Standard

Approved by the American National Standards Institute

August 16, 2018

Guide for the Joining of Solid Solution Austenitic

Stainless Steels

3rd Edition

Supersedes AWS G2.3M/G2.3:2012

Prepared by the American Welding Society (AWS) G2 Committee on Joining of Metals and Alloys

Under the Direction of the AWS Technical Activities Committee

Approved by the AWS Board of Directors

Abstract

This guide presents a description of solid solution austenitic stainless steels and the processes and procedures that can be used for the joining of these materials. This standard discusses the welding processes and welding parameters, qualifica- tions, inspection and repair methods, cleaning, and safety considerations. Practical information has been included in the form of figures, tables, and graphs that should prove useful in determining capabilities and limitations in the joining of austenitic stainless steels.

ISBN Print: 978-1-64322-016-1

ISBN PDF: 978-1-64300-017-8

© 2018 by American Welding Society

All rights reserved Printed in the United States of America

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Official interpretations of any of the technical requirements of this standard may only be obtained by sending a request, in writing, to the appropriate technical committee. Such requests should be addressed to the American Welding Society, Attention: Managing Director, Standards Development, 8669 NW 36 St, # 130, Miami, FL 33166 (see Annex G). With regard to technical inquiries made concerning AWS standards, oral opinions on AWS standards may be rendered. These opinions are offered solely as a convenience to users of this standard, and they do not constitute professional advice. Such opinions represent only the personal opinions of the particular individuals giving them. These individuals do not speak on behalf of AWS, nor do these oral opinions constitute official or unofficial opinions or interpretations of AWS. In addition, oral opinions are informal and should not be used as a substitute for an official interpretation.

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Personnel

AWS G2 Committee on Joining of Metals and Alloys

W. Layo, Chair Midalloy

G. Dunn, Vice Chair ExxonMobil Production Company

1. N. Borrero, Secretary American Welding Society

   S. O. Luke Black & Veatch

   1. C. Sutherlin ATI Wah Chang

      D. J. Tillack Consultant to Nickel Institute

      
      

      AWS G2E Subcommittee on Stainless Steel Alloys

   2. O. Luke, Chair Black & Veatch

1. N. Borrero, Secretary American Welding Society

   1. L. Colwell Bechtel Corporation

   2. M. Fragano Air Products and Chemicals, Incorporated

D. W. Haynie Kobelco Welding of America, Incorporated

W. E. Layo Midalloy

1. W. Record Townley Foundry & Machine

   1. D. Ross ESAB Welding and Cutting Products

   2. Singh GE Oil & Gas

J. W. Sowards National Institute of Standards and Technology

D. J. Tillack Consultant to Nickel Institute

M. D. Yaple Böhler Welding Group USA, Incorporated

Advisor to the AWS G2E Subcommittee on Stainless Steel Alloys

R. D. Fuchs Voestalpine Böhler Welding USA, Incorporated

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Foreword

This foreword is not part of this standard but is included for informational purposes only.

The American Welding Society formed the G2 Committee on the Joining of Metals and Alloys in 1992 in response to an industry demand for information on welding the metals and alloys that have not been covered by other documents and committees. This document is written by the G2 Committee on the Joining of Metals and Alloys.

NOTE: The user’s attention is called to the possibility that compliance with this standard may require use of an invention covered by patent rights.

By publication of this standard, no position is taken with respect to the validity of any such claim(s) or of any patent rights in connection therewith. If a patent holder has filed a statement of willingness to grant a license under these rights on reasonable and nondiscriminatory terms and conditions to applicants desiring to obtain such a license, then details may be obtained from the standards developer.

A vertical line in the margin or underlined text in clauses, tables, or figures indicates an editorial or technical change from the 2012 edition.

Comments and suggestions for the improvement of this standard are welcome. They should be sent to the Secretary, AWS G2 Committee on Joining of Metals and Alloys, American Welding Society, 8669 NW 36 St, # 130, Miami, FL 33166.

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Table of Contents

Page No.

Personnel v

Foreword vii

List of Tables xi

List of Figures xii

1. General Requirements 1

   1. Scope. 1

   2. Units of Measure. 1

   3. Safety 1

2. Normative References 2

3. Terms and Definitions 2

4. General Information 4

   1. History 4

   2. Properties 8

   3. Product Forms 8

   4. Specifications 8

5. Metallurgy 15

   1. Ferrite Discussion 15

   2. The Ferrite-Sigma Phase Relationship 21

   3. Corrosion Resistance Related to Welding 22

   4. Heat Tint 23

6. Welding and Fabrication Considerations 24

   1. Weld Joint Design 24

   2. Cleaning Prior to Welding 25

   3. Thermal Arc Gouging and Grinding. 26

   4. Distortion Control 27

   5. Welding Preheat and Maximum Interpass Temperature 28

   6. Welding Position 28

   7. Root Pass Welding 28

   8. Shielding Gas and Cleanliness. 32

7. Weldability Considerations 32

   1. Solidification Cracking 32

   2. Reheat Cracking in Type 347-SS 33

   3. Other Forms of Weld Cracking and Prevention Strategies 33

   4. Reheat Cracking in FCAW Deposits 34

8. Welding Processes 34

   1. Shielded Metal Arc Welding (SMAW) 34

   2. Gas Tungsten Arc Welding (GTAW) 40

   3. Gas Metal Arc Welding (GMAW) 44

   4. Flux Cored Arc Welding (GCAW) 52

   5. Submerged Arc Welding (SAW) 56

   6. Plasma Arc Welding (PAW) 58

      Page No.

   7. Laser Beam Welding (LBW) and Electron Beam Welding (EBW) 59

   8. Resistance Welding 59

   9. Brazing 59

9. Postweld Operations 60

   1. Visual Examination 60

   2. Weld Size 60

   3. Final Visual Examination 60

   4. Weld Discontinuities 60

   5. Slag Removal 61

   6. Grinding and Finishing Techniques 61

   7. Media Blasting 61

   8. Cleaning, Pickling, and Passivation 62

   9. Electropolishing 64

10. Heat Treatment 65

    1. Solution Annealing 65

    2. Stress Relief 65

    3. Stabilization Anneal 66

11. Storage and Shipping Recommendations 67

12. Maintenance and Repair 67

    1. Maintenance 67

    2. Repair 68

Annex A (Informative)—Suggested Filler Metal Selection Chart 71

Annex B (Informative)—Informative References 79

Annex C (Informative)—ASTM Base Metal Specifications for Austenitic Stainless Steels 83

Annex D (Informative)—Estimating the Ferrite Content of Cast Base Materials 87

Annex E (Informative)—Engineering Terms, Common Conversions, and SMAW Electrode Diameters 89

Annex F (Informative)—Example Purchase Specification Topics 93

Annex G (Informative)—Requesting an Official Interpretation on an AWS Standard 95

List of AWS Documents on the Joining of Metals and Alloys 97

List of Tables

Table Page No.

1. The Chemical Composition Limits of Common Wrought Austenitic Stainless Steel Base Materials 5

2. The Chemical Composition Limits of Common Cast Austenitic Stainless Steel Base Materials 9

3. Mechanical Properties of Wrought Annealed Stainless Steel Alloys 12

4. Minimum Mechanical Properties of Common Cast Austenitic Stainless Steel Base Materials 14

5.1 Ferrite Diagram Comparisons of Chrome and Nickel Equivalencies 19

1. Typical Physical Property Comparisons of Austenitic Stainless Steels versus Carbon Steels 27

2. Purging Guidelines for Piping 31

1. Chemical Composition of Undiluted SMAW Weld Deposits 35

2. All-Weld-Metal Mechanical Property Requirements Undiluted SMAW Weld Deposits

   (AWS A5.4/A5.4M) 37

3. SMAW Electrodes: Welding Current, Position of Welding, and Operating Characteristics 38

4. SMAW Electrodes: Suggested Current Ranges for E3xx-15, -16, and -17 Type Electrodes 39

5. Tungsten Amperage Limits, GTAW 41

6. Suggested Argon Torch Flow Rates, Manual GTAW 42

7. Suggested Gas Cup Size versus Maximum Welding Current, Manual GTAW 42

8. GTAW (TIG) Shielding Gas Selection 43

9. Chemical Compositions of Bare Stainless Steel Filler Metals (AWS A5.9/A5.9M) and of

   Metal Cored Filler Metal Deposits (AWS A5.22/A5.22M) 45

10. Nickel-Based Consumables, Chemical Composition Ranges 47

11. Nickel-Based SMAW Electrodes, Specified Tensile Properties 48

12. GMAW (MIG) Shielding Gas Selection 49

13. GMAW Parameters (Short Circuit, DCEP, He + 7.5%Ar + 2.5%CO2 Shielding Gas) 50

14. GMAW Parameters (Spray Transfer, DCEP, 98%Ar + 2%O2 Shielding Gas) 50

15. FCAW Electrodes Classification Scheme (AWS A5.22/A5.22M:2012) 52

16. Stainless Steel Weld Deposit Composition Requirements for FCAW Electrodes and Rods

    (AWS A5.22/A5.22M) 53

17. Stainless Steel Weld Deposit Tensile Requirements for Flux Cored Electrodes and Rods

    (AWS A5.22/A5.22M) 55

18. Shielding Gas Selection for Flux Cored Arc Welding 55

19. Typical Submerged Arc Welding Parameters, DCEP 58

1. Suggested Filler Metal Selection Chart—Wrought Standard Grades 73

2. Suggested Filler Metal Selection Chart—Wrought Proprietary Grades 76

3. Filler Selection for Stainless Steel Castings 77

1. Common Engineering Terms 89

2. Data 89

3. Common Welding-Related Conversion Factors 90

List of Figures

Figure Page No.

4.1 Alloying Variations of Common Austenitic Stainless Steels 7

1. The Schaeffler Diagram 16

2. The DeLong Diagram 17

3. WRC-1992 Diagram for Stainless Steel Weld Metal 18

4. a Carbide Precipitation in Type 304 Austenitic Stainless Steel 23

5.4b Carbide Reaction Temperature Ranges 24

D.1 The Schoefer Diagram 87

Guide for the Joining of

Solid Solution Austenitic Stainless Steels

1. General Requirements

   1. Scope. This guide presents a description of solid solution austenitic stainless steels and the most commonly used welding processes and procedures for joining these materials. The most commonly used welding processes, including shielded metal arc welding (SMAW), gas tungsten arc welding (GTAW), gas metal arc welding (GMAW), submerged arc welding (SAW), and flux cored arc welding (FCAW), are discussed in detail; laser beam, electron beam, plasma arc, resistance, and braze welding are not covered in great detail.

      
      

      The welding processes discussed in this guide include recommended welding parameters, filler metals, shielding gases, and fluxes. Procedure qualifications, inspection and repair considerations and methods, and cleaning and safety consid- erations are also discussed. Practical information has been included as figures, tables, and graphs that should prove use- ful for determining the capabilities and limitations in the joining of austenitic stainless steels. This guide does not address martensitic, ferritic, or duplex stainless steels.

      
      

      Although this guide is not written with mandatory requirements, mandatory language, such as the use of “shall,” will be found in those portions of the document where failure to follow the instructions or procedures could produce inferior, misleading, or unsafe results.

      
      

   2. Units of Measure. This standard uses both the International System of Units (SI) and U.S. Customary Units. The lat- ter are shown with brackets ([ ]) or in appropriate columns in tables and figures. The measurements may not be exact equivalents; therefore, each system should be used independently.

      
      

   3. Safety. Safety and health issues and concerns are beyond the scope of this standard; some safety and health informa- tion is provided, but such issues are not fully addressed herein.

      
      

      Safety and health information is available from the following sources: American Welding Society:

      1. ANSI Z49.1, Safety in Welding, Cutting, and Allied Processes

         
         

      2. AWS Safety and Health Fact Sheets

         
         

      3. Other safety and health information on the AWS website Material or Equipment Manufacturers:

1. Safety Data Sheets supplied by materials manufacturers

   
   

2. Operating Manuals supplied by equipment manufacturers Applicable Regulatory Agencies

Work performed in accordance with this standard may involve the use of materials that have been deemed hazardous and may involve operations or equipment that may cause injury or death. This standard does not purport to address all safety and health risks that may be encountered. The user of this standard should establish an appropriate safety program to address such risks as well as to meet applicable regulatory requirements. ANSI Z49.1 should be considered when devel- oping the safety program.