1、Recommended Practices for Gas Tungsten Arc Welding AWS C5.5/C5.5M:2003 An American National Standard550 N.W. LeJeune Road, Miami, Florida 33126 AWS C5.5/C5.5M:2003 An American National Standard Approved by American National Standards Institute June 4, 2003 Recommended Practices for Gas Tungsten Arc
2、Welding Supersedes A WS C5.5-80 Prepared by AWS C5 Committee on Arc Welding and Arc Cutting Under the Direction of AWS Technical Activities Committee Approved by AWS Board of Directors Abstract This document is designed to assist anyone who is associated with gas tungsten arc welding (GTAW). This in
3、cludes welders, welding technicians, welding engineers, quality control personnel, welding supervisors, purchasing personnel, educators, and students. This document discusses welding principles, equipment, gas shielding, and techniques for manual and automatic GTAW. Welding safety, troubleshooting,
4、and related items are included for understanding by all types of personnel in establishing better production welding operations. Educators will find this publication a handy reference for teaching all aspects of gas tungsten arc welding. It can become a quick reference for students after their gradu
5、ation or during their employment. Key WordsGas tungsten arc welding, GTAW, TIG, training, process, qualification, equipment, quality, safe practices, WIG, Heliarc Statement on Use of AWS American National Standards All standards (codes, specifications, recommended practices, methods, classifications
6、, and guides) of the American Welding Society (AWS) are voluntary consensus standards that have been developed in accordance with the rules of the American National Standards Institute (ANSI). When AWS standards are either incorporated in, or made part of, documents that are included in federal or s
7、tate laws and regulations, or the regulations of other governmental bodies, their provisions carry the full legal authority of the statute. In such cases, any changes in those AWS standards must be approved by the governmental body having statutory jurisdiction before they can become a part of those
8、 laws and regulations. In all cases, these standards carry the full legal authority of the contract or other document that invokes the AWS standards. Where this contractual relationship exists, changes in or deviations from requirements of an AWS standard must be by agreement between the contracting
9、 parties. International Standard Book Number: 0-87171-715-8 American Welding Society, 550 N.W. LeJeune Road, Miami, FL 33126 2003 by American Welding Society. All rights reserved Printed in the United States of America AWS American National Standards are developed through a consensus standards devel
10、opment process that brings together volunteers representing varied viewpoints and interests to achieve consensus. While AWS administers the process and establishes rules to promote fairness in the development of consensus, it does not independently test, evaluate, or verify the accuracy of any infor
11、mation or the soundness of any judgments contained in its standards. AWS disclaims liability for any injury to persons or to property, or other damages of any nature whatsoever, whether spe- cial, indirect, consequential or compensatory, directly or indirectly resulting from the publication, use of,
12、 or reliance on this standard. AWS also makes no guaranty or warranty as to the accuracy or completeness of any information published herein. In issuing and making this standard available, AWS is not undertaking to render professional or other services for or on behalf of any person or entity. Nor i
13、s AWS undertaking to perform any duty owed by any person or entity to someone else. Anyone using these documents should rely on his or her own independent judgment or, as appropriate, seek the advice of a competent professional in determining the exercise of reasonable care in any given circumstance
14、s. This standard may be superseded by the issuance of new editions. Users should ensure that they have the latest edition. Publication of this standard does not authorize infringement of any patent. AWS disclaims liability for the infringement of any patent resulting from the use or reliance on this
15、 standard. Finally, AWS does not monitor, police, or enforce compliance with this standard, nor does it have the power to do so. On occasion, text, tables, or figures are printed incorrectly, constituting errata. Such errata, when discovered, are posted on the AWS web page (www.aws.org). Official in
16、terpretations of any of the technical requirements of this standard may be obtained by sending a request, in writing, to the Managing Director, Technical Services Division, American Welding Society, 550 N.W. LeJeune Road, Miami, FL 33126 (see Annex A). With regard to technical inquiries made concern
17、ing AWS standards, oral opinions on AWS standards may be rendered. However, 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 inter- p
18、retations of AWS. In addition, oral opinions are informal and should not be used as a substitute for an official interpretation. This standard is subject to revision at any time by the AWS C5 Committee on Arc Welding and Arc Cutting. It must be reviewed every five years, and if not revised, it must
19、be either reapproved or withdrawn. Comments (recommendations, additions, or deletions) and any pertinent data that may be of use in improving this standard are required and should be addressed to AWS Headquarters. Such comments will receive careful consideration by the AWS C5 Committee on Arc Weldin
20、g and Arc Cutting and the author of the comments will be informed of the Committees response to the com- ments. Guests are invited to attend all meetings of the AWS C5 Committee on Arc Welding and Arc Cutting to express their comments verbally. Procedures for appeal of an adverse decision concerning
21、 all such comments are provided in the Rules of Operation of the Technical Activities Committee. A copy of these Rules can be obtained from the American Welding Society, 550 N.W. LeJeune Road, Miami, FL 33126. Photocopy Rights Authorization to photocopy items for internal, personal, or educational c
22、lassroom use only, or the internal, personal, or educational classroom use only of specific clients, is granted by the American Welding Society (AWS) provided that the appropriate fee is paid to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, Tel: 978-750-8400; online: http:/.
23、iii Personnel A WS C5 Committee on Arc Welding and Arc Cutting J. R. Hannahs, Chair Edison Community College N. A. Sanders, 1st Vice Chair Hypertherm, Incorporated D. B. Holliday, 2nd Vice Chair Northrop Grumman Corporation P . Howe, Secretary American Welding Society *E. R. Bohnart Welding Educatio
24、n and Consulting H. A. Chambers TRW Nelson Stud Welding Division C. Connelly Poly-Weld, Incorporated J. DeVito ESAB Welding and Cutting Products R. M. Dull Edison Welding Institute D. A. Fink The Lincoln Electric Company I. D. Harris Edison Welding Institute *R. T. Hemzacek Consultant G. K. Hicken S
25、andia National Laboratory, Retired K. Y. Lee The Lincoln Electric Company R. P . Munz The Lincoln Electric Company S. R. Potter SRP Consulting Services *B. L. Shultz The Taylor-Winfield Corporation R. L. Strohl Tweco-Arcair Corporation *E. G. Yevick Weld-Met International Group L. Yost The Lincoln E
26、lectric Company A WS C5C Subcommittee on Gas Tungsten Arc Welding G. K. Hicken, Chair Sandia National Laboratories, Retired R. D. Campbell, Vice Chair Purity Systems, Incorporated P . Howe, Secretary American Welding Society E. A. Benway Swagelok Company *E. R. Bohnart Welding and Education Consulti
27、ng *C. Connelly Poly-Weld, Incorporated D. E. Destefan High Current Technologies, Incorporated R. W. Diesner Retired J. C. Downey Retired T. W. Edwards American Welding and Engineering, Incorporated *J. R. Hannahs Edison Community College *L. M. Hellemann General Electric Aircraft Engines E. J. LaCo
28、ursiere EJL & Associates P . C. McClay Pratt and Whitney D. E. Spragg Pratt and Whitney *J. S. Thrower Optimum Engineering Manufacturing, Incorporated D. A. Wright Zephyr Products, Incorporated *B. Young Westinghouse Savannah River Company, Retired *AdvisorThis page is intentionally blank.v Foreword
29、 (This Foreword is not a part of AWS C5.5/C5.5M:2003, Recommended Practices for Gas Tungsten Arc Welding, but is included for informational purposes only.) Gas tungsten arc welding (GTAW) was introduced as a practical fabricating process in the 1940s. In the decades since then, advances have been ma
30、de in the equipment and in the development of techniques for automatic applications. GTAW is now accepted as the only practical joining method in some metal joining applications. These recommended practices were first prepared by the AWS C5 Committee on Arc Welding and Arc Cutting and the AWS C5C Su
31、bcommittee on Gas Tungsten Arc Welding in 1980. The 1980 edition was reaffirmed in 1989. The current AWS C5 Committee on Arc Welding and Arc Cutting and the current C5C Subcommittee on GTAW have prepared these recommended practices to present the basic practices and methods of GTAW and to expand the
32、 document to include the latest advancements in this process. These recommended practices are based on present uses of GTAW in the metal fabricating industry, along with research and development and new applications of the process. We should all encourage our younger generation to consider welding a
33、nd welding related fields as places to become involved with the high rewards and challenges to be encountered in the future. We should also be willing and pleased to share our prior experiences and knowledge that could help new members excel in this occupation. The description of GTAW and its featur
34、es are presented here as clearly and concisely as possible. The Committee has developed these guidelines in the hope that they would lead to further development of the GTAW process and, thus, to higher quality and performance standards. Comments and suggestions for the improvement of this standard a
35、re welcomed. They should be sent to the Secretary, AWS C5 Committee on Arc Welding and Arc Cutting, American Welding Society, 550 N.W. LeJeune Road, Miami, FL 33126. Official interpretations of any of the technical requirements of this standard may be obtained by sending a request, in writing, to th
36、e Managing Director, Technical Services Division, American Welding Society. A formal reply will be issued after it has been reviewed by the appropriate personnel following established procedures. Guidelines for technical inquiries regarding AWS standards are shown in Annex A. This document will be r
37、eviewed periodically to assure its success in serving all parties concerned with its provisions. Revisions will be issued when warranted.This page is intentionally blank.vii Table of Contents Page No. Personnel iii Foreword.v List of Tables.x List of Figuresxi 1. Scope and Introduction 1 1.1 Scope .
38、1 1.2 Introduction to the Gas Tungsten Arc Welding (GTAW) Process.1 1.3 History.1 2. Normative References4 2.1 American Conference of Governmental Industrial Hygienists Standards 5 2.2 AWS Standards5 2.3 ISO Standards6 2.4 OSHA Standards .6 3. Definitions.6 4. GTAW Principles .9 4.1 Process Descript
39、ion .9 4.2 Process Advantages.9 4.3 Process Limitations .11 4.4 Process Variables.12 4.5 Related Variables.17 5. Equipment and Supplies.18 5.1 Welding Power Sources (Used for GTAW)Introduction .18 5.2 Controllers.20 5.3 Pulse Controllers .22 5.4 Weld Sequence Controllers .22 5.5 Arc Welding Torches.
40、23 5.6 Wire Feeders30 5.7 Arc and Torch Oscillators31 5.8 Arc Initiation Equipment.32 6. Tungsten Electrodes .33 6.1 General 33 6.2 Classifications of Electrodes .34 6.3 Surface Finishes 37 6.4 Electrode Sizes and Current Capacities 37 6.5 Electrode Tip Configurations 38 6.6 Electrode Cutting.41 6.7
41、 Factors Affecting Electrode Life.41 6.8 Removing Contamination .42 6.9 Grinding Dust42 6.10 Storage.43 7. Gas Shielding, Purging, and Backing 43 7.1 Torch Shielding Gas 43viii Page No. 7.2 Purging 50 7.3 Shielding and Purging Gas Purity .62 7.4 Shielding and Purging Gas Economics .65 7.5 Purifiers
42、.65 7.6 Purging Gas Safety67 8. Fixturing and Tooling.68 8.1 Material Selection .68 8.2 Tooling/Fixturing Considerations68 8.3 Temporary (Soft)/Permanent (Hard) Tooling69 9. Welding Techniques .71 9.1 General 71 9.2 Manual and Semiautomatic Welding 71 9.3 Mechanized Welding.80 9.4 Automated Welding.
43、83 10. Joint Design, Preparation, and Welding Positions .85 10.1 Introduction .85 10.2 Basic Joint Configurations and Welding Positions .85 10.3 Edge Preparation and Surface Cleaning85 11. Welding Characteristics of Selected Alloys.85 11.1 Introduction .85 11.2 Carbon and Alloy Steels89 11.3 Stainle
44、ss Steels and Iron-Based Superalloys.89 11.4 Aluminum Alloys90 11.5 Magnesium Alloys 91 11.6 Beryllium.91 11.7 Copper Alloys .91 11.8 Nickel Alloys.92 11.9 Cobalt Alloys.92 11.10 Refractory and Reactive Metals 92 11.11 Cast Irons.92 11.12 Welding Dissimilar Materials92 11.13 Filler Metals 92 12. Qua
45、lification of Procedures, Welders, and Welding Operators94 12.1 Introduction .94 12.2 Welding Program.95 12.3 Establishing Welding Requirements .95 12.4 Welding Procedure Specifications (WPS).95 12.5 Procedure Qualification Records (PQR) .95 12.6 Welder and Welding Operator Qualification Tests95 13.
46、 Quality Control 96 13.1 Introduction .96 13.2 Weldment Quality96 13.3 Specifications 96 14. Troubleshooting .97 14.1 General 97 14.2 Electrical97 14.3 Inert Shielding Gas Troubleshooting 102 14.4 Water Cooling Systems .105 14.5 Tools and Fixtures .106ix Page No. 14.6 Filler Material106 14.7 Design
47、of Welded Assemblies.106 14.8 Weld Joint Fit-up.108 15. Safety .108 15.1 Hazards108 15.2 Electrical Shock.108 15.3 Arc Radiation and Burns.108 15.4 Welding Environment109 15.5 Oxygen Deficiency110 15.6 Noise110 15.7 Safe Handling of Cylinders.110 15.8 Fires And Explosions 110 15.9 Common Sense110 15
48、.10 Grinding Dust110 Nonmandatory Annexes113 Annex AGuidelines for Preparation of Technical Inquiries for AWS Technical Committees113 Annex BSuggested Reading List and Other References115 List of AWS Documents on Arc Welding and Arc Cutting 117x List of Tables Table Page No. 1 Welding Process Compar
49、ison Based on Quality and Economics 11 2 Comparison of Typical Current Ratings for Gas-Cooled and Water-Cooled GTAW Torches.25 3 Typical Welding Cable Capacities .29 4 Guide for Selecting the Size of Cable Based on the Welding Current.30 5 Chemical Composition Requirements for Tungsten Electrodes 34 6 Typical Current Ranges for Tungsten Electrodes and Recommended Gas Cup Sizes 35 7 Comparison of Surface Finish Designations37 8 Recommended Types of Current, Tungsten Electrodes, and Shielding Gases for Welding of Various Metals and Alloys .39 9 Tungsten Electrode Tip Sh
