AWS C3.9M/C3.9:2009

An American National Standard

Specification for Resistance Brazing

AWS C3.9M/C3.9:2009

An American National Standard

Approved by the American National Standards Institute

July 30, 2008

Specification for Resistance Brazing

1st Edition

Prepared by the American Welding Society (AWS) C3 Committee on Brazing and Soldering

Under the Direction of the AWS Technical Activities Committee

Approved by the AWS Board of Directors

Abstract

This specification provides the minimum fabrication, equipment, material, and process procedure requirements, as well as discontinuity limits for the resistance brazing of steels, copper, copper alloys, heat- and corrosion-resistant alloys, and other materials that can be adequately resistance brazed (the resistance brazing of aluminum alloys is addressed in AWS C3.7M/C3.7, Specification for Aluminum Brazing). This specification provides criteria for classifying resistance brazed joints based on loading and the consequences of failure and quality assurance criteria defining the limits of acceptability in each class. This specification defines acceptable resistance brazing equipment, materials, and procedures, as well as the required inspection for each class of joint.

550 N.W. LeJeune Road, Miami, FL 33126

International Standard Book Number: 978-0-87171-510-4

American Welding Society 550 N.W. LeJeune Road, Miami, FL 33126

© 2008 by American Welding Society

All rights reserved Printed in the United States of America

Photocopy Rights. No portion of this standard may be reproduced, stored in a retrieval system, or transmitted in any form, including mechanical, photocopying, recording, or otherwise, without the prior written permission of the copyright owner.

Authorization to photocopy items for internal, personal, or educational classroom use only or the internal, personal, or educational classroom use only of specific clients is granted by the American Welding Society provided that the appropriate fee is paid to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, tel: (978) 750-8400; Internet:

<www.copyright.com>.

ii

Statement on the Use of American Welding Society Standards

All standards (codes, specifications, recommended practices, methods, classifications, 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 American National Standards are either incorporated in, or made part of, documents that are included in federal or state laws and regulations, or the regulations of other govern- mental 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 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 parties.

AWS American National Standards are developed through a consensus standards development process that brings together volunteers representing varied viewpoints and interests to achieve consensus. While the AWS administers the process and establishes rules to promote fairness in the development of consensus, it does not independently test, evalu- ate, or verify the accuracy of any information 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 special, indirect, consequential, or compensatory, directly or indirectly resulting from the publication, use of, or reliance on this standard. AWS also makes no guarantee or warranty as to the accuracy or completeness of any information published herein.

In issuing and making this standard available, AWS is neither undertaking to render professional or other services for or on behalf of any person or entity, nor is 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 circumstances. It is assumed that the use of this standard and its provisions are entrusted to appropriately qualified and competent personnel.

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 or trade name. Users of this standard accept any and all liabilities for infringement of any patent or trade name items. AWS disclaims liability for the infringement of any patent or product trade name resulting from the use of this standard.

Finally, the 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 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, Technical Services Division, 550 N.W. LeJeune Road, Miami, FL 33126 (see Annex B). 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.

This standard is subject to revision at any time by the AWS C3 Committee on Brazing and Soldering. It must be reviewed every five years, and if not revised, it must be either reaffirmed 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 C3 Committee on Brazing and Solder- ing and the author of the comments will be informed of the Committee’s response to the comments. Guests are invited to attend all meetings of the AWS C3 Committee on Brazing and Soldering to express their comments verbally. Procedures for appeal of an adverse decision concerning 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.

iii

This page is intentionally blank.

iv

iv

Personnel

AWS C3 Committee on Brazing and Soldering

P. T. Vianco, Chair Sandia National Laboratories

1. W. Smith, Vice Chair Materials Resources International

2. N. Borrero, Secretary American Welding Society

   G. L. Alexy The Prince & Izant Company

   K. Allen Bellman-Melcor

   R. Aluru Chromalloy Gas Turbine Corporation

   B. Barten Delphi Thermal & Interior

   D. W. Bucholz Conforma Clad, Incorporated

   D. E. Budinger General Electric Aviation

   C. F. Darling Lucas-Milhaupt, Incorporated

   W. J. Engeron Engineered Alloy & Systems Support

   S. L. Feldbauer Abbott Furnace Company

   Y. Flom NASA Goddard Space Flight Center

   D. Fortuna Sulzer Metco (U.S.), Incorporated

   B. Freund Millennium Industries

   Y. Gao Pratt & Whitney Rocketdyne

   1. A. Gross Gourley Curtiss-Wright

   2. R. Hazelbaker The Prince & Izant Company

   3. P. Hirthe Kru-Mar Manufacturing Services

F. M. Hosking Sandia National Laboratories

J. R. Jachna Modine Manufacturing Company

D. A. Javernick Los Alamos National Laboratory

G. F. Kayser Pratt & Whitney Rocketdyne

M. J. Kuta Lucas-Milhaupt, Incorporated

E. Liguori Scarrott Metallurgical

M. J. Lucas, Jr. MattBraze Consulting

R. P. McKinney The Prince & Izant Company

W. Miglietti General Electric Aviation

C. R. Moyer Bodycote Thermal Processing

T. Oyama WESGO Metals

1. A. Paponetti, Sr. Expert Brazing & Heat Treating, Incorporated

   1. L. Peaslee Wall Colmonoy Corporation

      M. Pohlman Honeywell Aerospace

      A. Rabinkin Metglas, Incorporated/Hitachi Metals

      1. E. Shapiro Titanium Brazing, Incorporated

         C. Walker Sandia National Laboratories

         
         

         Advisors to the AWS C3 Committee on Brazing and Soldering

         1. Belohlav Lucas-Milhaupt, Incorporated

   2. S. Bhargava American Axle & Manufacturing Company

S. Christy Pratt & Whitney

N. C. Cole NCC Engineering

C. E. Fuerstenau Lucas-Milhaupt, Incorporated

P. K. Gupta Honeywell Aerospace

M. J. Higgins Consultant

v

Advisors to the AWS C3 Committee on Brazing and Soldering (Continued)

H. Lichtenberger Williams Advanced Materials

E. Lugscheider Aachen University of Technology

W. D. Rupert Wolverine Joining Technologies

AWS C3D Subcommittee on Brazing Specifications

J. R. Jachna, Chair Modine Manufacturing Company

1. J. Pohlman, Vice Chair Honeywell Aerospace

   1. N. Borrero, Secretary American Welding Society

      R. Aluru Chromalloy Gas Turbine Corporation

      D. E. Budinger General Electric Aviation

      1. L. Feldbauer Abbott Furnace Company

         Y. Flom NASA Goddard Space Flight Center

         1. Freund Millennium Industries

         2. E. Fuerstenau Lucas-Milhaupt, Incorporated

      Y. P. Gao Pratt & Whitney Rockeydyne

      1. A. Gross Gourley Curtiss-Wright

      2. R. Hazelbaker The Prince & Izant Company

      3. P. Hirthe Kru-Mar Manufacturing Services

1. M. Hosking Sandia National Laboratories

2. F. Kayser Pratt & Whitney Rockeydyne

M. J. Kuta Lucas-Milhaupt, Incorporated

E. Liguori Scarrott Metallurgical

J. A. Liguori Scarrott Metallurgical

M. J. Lucas, Jr. MattBraze Consulting

R. P. McKinney The Prince & Izant Company

C. R. Moyer Bodycote Thermal Processing

J. Newman Laser Technology, Incorporated

T. Oyama WESGO Metals

C. A. Paponetti, Sr. Expert Brazing and Heat Treating, Incorporated

R. L. Peaslee Wall Colmonoy Corporation

R. W. Smith Materials Resources International

P. T. Vianco Sandia National Laboratories

C. M. Volpe Wolverine Joining Technologies

C. Walker Sandia National Laboratories

C. Wohlmuth Consultant

Advisors to the AWS C3D Subcommittee on Brazing Specifications

B. Barten Delphi Thermal & Interior

A. B. Cedilote Wabco, Incorporated

N. C. Cole NCC Engineering

P. K. Gupta Honeywell Aerospace

M. J. Higgins Consultant

T. A. Kern Consultant

H. H. Lang York International Corporation

H. Mizuhara Consultant

W. D. Rupert Wolverine Joining Technologies

K. P. Thornberry Care Medical, Incorporated

R. W. Walls Walls Engineering

vi

Foreword

This foreword is not part of AWS C3.9M/C3.9:2009, Specification for Resistance Brazing, but is included for informational purposes only.

This specification is one of a series prepared at the request of the Aerospace Materials Division (AMD) of the Society of Automotive Engineers (SAE) and a number of other organizations to replace the military specification MIL-B-7883, Brazing of Steels, Copper, Copper Alloys, Nickel Alloys, Aluminum, and Aluminum Alloys, which addressed all brazing processes. It became both obsolete and very cumbersome as brazing technology proliferated and became more complex.

Addressing all of the diverse brazing processes in one concise, easily understood document was found to be impractical; therefore, a series of six independent specifications on brazing have been written, all in the same format. These are AWS C3.4M/C3.4, Specification for Torch Brazing; AWS C3.5M/C3.5, Specification for Induction Brazing; AWS C3.6M/C3.6, Specification for Furnace Brazing; AWS C3.7M/C3.7, Specification for Aluminum Brazing; AWS C3.8M/C3.8, Specification for the Ultrasonic Examination of Brazed Joints; and the present document, AWS C3.9M/C3.9, Specification for Resistance Brazing.

The decision to subdivide the technology in this way was based on a survey of production brazing applications con- ducted by the AWS C3 Committee on Brazing and Soldering. The survey demonstrated that these six specifications would cover the vast majority of brazing performed today.

After the completion of the fourth brazing specification, it was determined that a document providing specific criteria and requirements for the application of ultrasonic testing to brazed joints was needed. Therefore, AWS C3.8M/C3.8, Specification for the Ultrasonic Examination of Brazed Joints, was written to complement this series.

AWS C3.9M/C3.9, Specification for Resistance Brazing, has been added to this group of diverse standards on brazing processes because resistance brazing is an additional commercial brazing method used in many industries. The specifics for this method are detailed in the same manner as the other five independent brazing specifications.

Comments and suggestions for the improvement of this standard are welcome. They should be sent to the Secretary, AWS C3 Committee on Brazing and Soldering, American Welding Society, 550 N.W. LeJeune Road, Miami, FL 33126.

vii

This page is intentionally blank.

viii

viii

Table of Contents

Page No.

Personnel v

Foreword vii

1. Scope 1

2. Normative References 1

3. Terms and Definitions 2

4. Classification of Brazed Joints 2

   1. Method of Classification 2

   2. Class A Joints 2

   3. Class B Joints 2

   4. Class C Joints 2

   5. No Class Specified 3

5. Process Requirements 3

   1. Process Description 3

   2. Equipment 3

   3. Materials 4

   4. Procedure Requirements 4

   5. Qualification 5

   6. Safety and Health 5

6. Quality Assurance Provisions 5

   1. Responsibility for Inspection 5

   2. Requirements for Compliance 5

   3. Sequence of Inspection and Manufacturing Operations 5

   4. Required Inspection of Brazed Joints 6

   5. Acceptance Criteria 7

   6. Process Completion 8

Annex A (Informative)—Informative References 9

Annex B (Informative)—Guidelines for the Preparation of Technical Inquiries 11

List of AWS Documents on Brazing and Soldering 13

ix

This page is intentionally blank.

x

x

Specification for Resistance Brazing

1. Scope

   This specification presents the minimum fabrication and quality requirements for the resistance brazing of materi- als such as steels, stainless steels, copper, copper alloys, and heat- or corrosion-resistant materials as well as other materials that can be adequately resistance brazed.

   
   

   The purpose of this specification is to standardize resis- tance brazing process requirements and control braze joint quality for all applications requiring brazed joints of assured quality. This document establishes the minimum requirements for processes and products with a minimum of explanatory information so that sources of ambiguity are minimized. It assigns responsibility for the ultimate quality of the brazed product to a single organization and permits that organization to modify requirements if appropriate to the application. It requires proper docu- mentation of any such modifications.

   
   

   Procedures for the protection of the safety and health of those performing resistance brazing and related opera- tions are of great importance. However, safety and health issues and concerns are beyond the scope of this standard and therefore are not fully addressed herein. Safety and health information is available from other sources, including, but not limited to, ANSI Z49.1, Safety in Welding, Cutting, and Allied Processes.

   
   

   This standard makes use of both the International System of Units (SI) and U.S. Customary Units. The latter are shown within brackets [ ], or in appropriate columns in tables and figures. The measurements may not be exact equivalents; therefore, each system shall be used independently.

   
   

2. Normative References

The standards listed below contain provisions that, through reference in this text, constitute mandatory pro- visions of this AWS standard. For undated references, the latest edition of the referenced standard shall apply.

For dated references, subsequent amendments to, or revi- sions of, any of these publications do not apply.

American Welding Society (AWS) standards:1

AWS A2.4, Symbols for Welding, Brazing, and Non- destructive Examination;

AWS A3.0, Standard Welding Terms and Definitions, Including Terms for Adhesive Bonding, Brazing, Solder- ing, Thermal Cutting, and Thermal Spraying;

AWS A5.8/A5.8M, Specification for Filler Metals for Brazing and Braze Welding;

AWS A5.31/A5.31M, Specification for Fluxes for Braze and Braze Welding;

AWS B2.2, Standard for Brazing Procedure and Per- formance Qualification;

AWS C3.3, Recommended Practices for the Design, Manufacture, and Examination of Critical Brazed Com- ponents; and

AWS C3.8M/C3.8, Specification for the Ultrasonic Examination of Brazed Joints.

American Society for Quality (ASQ) standard:2

ASQ Z1.4, Sampling Procedures and Tables for Inspection by Attributes.

SAE International/Aerospace Materials Division (AMD) standards:3

SAE AMS 2403, Plating, General Purpose;

SAE AMS 2424, Plating, Nickel, Low Stressed Deposit;

1 AWS standards are published by the American Welding Society, 550 N.W. LeJeune Road, Miami, FL 33126.

2 ASQ standards are published by the American Society for Quality (ASQ), 600 North Plankinton Avenue, Milwaukee, WI 53203-3005.

3 SAE International standards are published by the Society of Automotive Engineers, 400 Commonwealth Drive, Warrendale, PA 15096-0001.

1