1、AWS D8.9M:2012An American National StandardTest Methods forEvaluating theResistance SpotWelding Behaviorof AutomotiveSheet SteelMaterialsAWS D8.9M:2012An American National StandardApproved by theAmerican National Standards InstituteFebruary 22, 2012Test Methods for Evaluating theResistance Spot Weld
2、ing Behaviorof Automotive Sheet Steel Materials3rd EditionSupersedes AWS/SAE D8.9M:2002Prepared by theAmerican Welding Society (AWS) D8 Committee on Automotive WeldingUnder the Direction of theAWS Technical Activities CommitteeApproved by theAWS Board of DirectorsAbstractThis document presents stand
3、ard test methods for evaluating the resistance spot welding behavior of automotive sheetsteels. The document contains a number of tests and test methods useful in determining the resistance spot welding per-formance of coated and uncoated automotive sheet steels of all strength levels and compositio
4、ns. The test methods aredesigned to assess current range, electrode endurance, and weld properties of automotive sheet steels. The weld propertytests include tests for hold time sensitivity, weld hardness, shear tension strength, and cross tension strength.iiAWS D8.9M:2012International Standard Book
5、 Number: 978-0-87171-808-2American Welding Society550 N.W. LeJeune Road, Miami, FL 33126 2012 by American Welding SocietyAll rights reservedPrinted in the United States of AmericaPhotocopy Rights. No portion of this standard may be reproduced, stored in a retrieval system, or transmitted in anyform,
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7、ed by the American Welding Society provided that the appropriatefee is paid to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, tel: (978) 750-8400; Internet:.iiiAWS D8.9M:2012Statement on the Use of American Welding Society StandardsAll standards (codes, specifications, recomm
8、ended practices, methods, classifications, and guides) of the AmericanWelding Society (AWS) are voluntary consensus standards that have been developed in accordance with the rules of theAmerican National Standards Institute (ANSI). When AWS American National Standards are either incorporated in, orm
9、ade 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 AWSstandards must be approved by the governmental body having statu
10、tory jurisdiction before they can become a part ofthose laws and regulations. In all cases, these standards carry the full legal authority of the contract or other documentthat invokes the AWS standards. Where this contractual relationship exists, changes in or deviations from requirementsof an AWS
11、standard must be by agreement between the contracting parties.AWS American National Standards are developed through a consensus standards development process that bringstogether volunteers representing varied viewpoints and interests to achieve consensus. While the AWS administers theprocess and est
12、ablishes 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
13、any nature whatsoever, whetherspecial, indirect, consequential, or compensatory, directly or indirectly resulting from the publication, use of, or relianceon this standard. AWS also makes no guarantee or warranty as to the accuracy or completeness of any informationpublished herein.In issuing and ma
14、king this standard available, AWS is neither undertaking to render professional or other services for oron behalf of any person or entity, nor is AWS undertaking to perform any duty owed by any person or entity to someoneelse. Anyone using these documents should rely on his or her own independent ju
15、dgment or, as appropriate, seek theadvice of a competent professional in determining the exercise of reasonable care in any given circumstances. It isassumed that the use of this standard and its provisions is entrusted to appropriately qualified and competent personnel.This standard may be supersed
16、ed by the issuance of new editions. This standard may also be corrected through publicationof amendments or errata. It may also be supplemented by publication of addenda. Information on the latest editions ofAWS standards including amendments, errata, and addenda are posted on the AWS web page (www.
17、aws.org). Users shouldensure that they have the latest edition, amendments, errata, and addenda.Publication of this standard does not authorize infringement of any patent or trade name. Users of this standard acceptany and all liabilities for infringement of any patent or trade name items. AWS discl
18、aims liability for the infringement ofany patent or product trade name resulting from the use of this standard.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 e
19、rrata. Such errata, when discovered, are postedon 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 Ameri
20、can Welding Society,Attention: Managing Director, Technical Services Division, 550 N.W. LeJeune Road, Miami, FL 33126 (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 u
21、sers of this standard, and they do not constitute professionaladvice. Such opinions represent only the personal opinions of the particular individuals giving them. These individualsdo not speak on behalf of AWS, nor do these oral opinions constitute official or unofficial opinions or interpretations
22、 ofAWS. 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 D8 Committee on Automotive Welding. It must be reviewedevery five years, and if not revised, it must be either reaffirmed
23、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 addressedto AWS Headquarters. Such comments will receive careful consideration by the AWS D8 Committee on AutomotiveWelding and the author
24、of the comments will be informed of the Committees response to the comments. Guests are in-vited to attend all meetings of the AWS D8 Committee on Automotive Welding to express their comments verbally. Pro-cedures for appeal of an adverse decision concerning all such comments are provided in the Rul
25、es of Operation of theTechnical Activities Committee. A copy of these Rules can be obtained from the American Welding Society, 550 N.W.LeJeune Road, Miami, FL 33126.This page is intentionally blank.ivAWS D8.9M:2012vAWS D8.9M:2012PersonnelAWS D8 Committee on Automotive WeldingD. L. Galiher, Chair Tow
26、er InternationalT. Coon, 1st Vice Chair Ford Motor CompanyM. D. Tumuluru, 2nd Vice Chair U.S. SteelE. H. Abrams, Secretary American Welding SocietyG. Armstrong Yachiyo of Ontario Manufacturing, IncorporatedJ. E. Beckham Chrysler Group LLCJ. C. Bohr General MotorsW. H. Brafford Tuffaloy Products, Inc
27、orporatedJ. W. Dolfi ConsultantF. W. Hunt Hitachi America, LimitedJ. G. Hunt AET Integration, IncorporatedC. Jiang AET Integration, IncorporatedS. C. Kelley ArcelorMittalD. P. Kelly Fusion Welding SolutionsD. R. Kolodziej Ford Motor Company (Retired)D. F. Maatz, Jr. RoMan Engineering Services, Incor
28、poratedT. W. Morrissett RoMan Engineering Services, IncorporatedJ. S. Noruk Servo Robot CorporationW. F. Qualls ConsultantAdvisor to the AWS D8 Committee on Automotive WeldingJ. F. Hinrichs Friction Stir Link, IncorporatedAWS D8D Subcommittee on Automotive Resistance Spot WeldingJ.C. Bohr, Chair Gen
29、eral MotorsW. F. Qualls, 1st Vice Chair ConsultantH. Zhang, 2nd Vice Chair University of ToledoE. H. Abrams, Secretary American Welding SocietyJ. E. Beckham Chrysler Group LLCE. Biro ArcelorMittalW. H. Brafford Tuffaloy Products, IncorporatedT. Coon Ford Motor CompanyJ. W. Dolfi ConsultantJ. G. Hunt
30、 AET Integration, IncorporatedC. Jiang AET Integration, IncorporatedD. P. Kelly Fusion Welding SolutionsM. Kimchi Edison Welding InstituteM. Kuo ArcelorMittalD. F. Maatz, Jr. RoMan Engineering Services, IncorporatedT. W. Morrissett RoMan Engineering Services, IncorporatedT. V. Natale AK Steel Corpor
31、ationC. J. Orsette Fusion Welding SolutionsE. Pakalnins RoMan Engineering Services, IncorporatedW. Peterson Edison Welding InstituteviAWS D8.9M:2012N. S. Scotchmer Huys Industries LimitedT. Sparschu TMS SolutionsD. J. Spinella ALCOA Technical CenterM. D.Tumuluru U.S. SteelAdvisors to the AWS D8D Sub
32、committee on Automotive Resistance Spot WeldingW. H. Trojanowski Chrysler Group LLCM. Hebert General Motors (Retired)AWS D8D Subcommittee on Automotive Resistance Spot Welding (Continued)viiAWS D8.9M:2012ForewordThis foreword is not part of AWS D8.9M:2012, Test Methods for Evaluating the Resistance
33、Spot WeldingBehavior of Automotive Sheet Steel Materials, but is included for informational purposes only.Since its publication in 1997, the AWS D8.9 standard has been widely used by steel companies and automotive compa-nies alike to test the weldability of sheet steels for various automotive applic
34、ations. This document evolved from theAuto/Steel Partnership of the American Iron and Steel Institutes publication, Weld Quality Test Methods Manual. TheAWS D8D Subcommittee, which includes members of the Auto/Steel Partnerships Standardized Welding Test MethodTask Force, acknowledges the important
35、contributions made by the Auto/Steel Partnerships staff and members in thedevelopment and revision of this document.With the introduction of new advanced high strength steels into automotive production there is a strong need to test thesenew steels. Therefore, a set of weld schedules has been added
36、in this revision to address this need. Further, a new Designof Experiments (DoE) test method has been included to examine the robustness of advanced high strength steels to vari-ations in welding parameters that typically occur under shop-floor conditions. The procedure outlined in the DoE testingme
37、thod has been validated at four independent testing laboratories.This document not only contains test methods for evaluating the welding behavior of sheet steels, but also covers areasessential to using these test methods in obtaining an accurate assessment of the material and its welding attributes
38、.Listed below are the key test methods described in this document:Sampling and characterization of test materialEquipment setup and electrode installationElectrode conditioning and weld size stabilizationEndurance (electrode life) testingCurrent level/current range testingWeld property testingCurren
39、t break-through testingDesign of Experiments testingThe sampling and material characterization procedures, equipment setup and electrode installation procedures, and elec-trode conditioning/weld size stabilization procedures are common to all test methods. In the endurance test, the “endur-ance limi
40、t” (defined as the number of acceptable welds made during the test) is the key welding performance measurethat is determined by this test. Other welding behavior measures determined in this test are current levels and currentrange. Weld button characteristics are assessed by destructive peel testing
41、 of weld samples.The weld property tests are designed to determine hold-time sensitivity, weld button fracture mode, shear tensionstrength, cross tension strength, metallurgical properties, and hardness of welds made with the test material. The weldproperty testing is now required at two different w
42、eld sizes. Proper judgment should be exercised when interpreting theresults of the weld property tests on higher strength steels (such as those with ultimate tensile strength greater than 500MPa), especially with tests run at the minimum weld size. Welds in such higher strength steels may show inter
43、facialfractures even at short hold times, especially at thicker gauges. The requirement to conduct the tests at the minimumweld size is included to generate more complete information on the behavior of such steels. A fracture classificationchart has been added as an Annex D.viiiAWS D8.9M:2012Current
44、 levels and current range are also determined during the weld property tests. The current break-through test isdesigned to evaluate the effects that sheet lubricants, conductive paints, or other surface treatments have on the initiationof spot welding current and nugget formation. The types of tests
45、 to use shall be specified by the party for whom thetesting is to be performed. For some steels, all tests may be specified, while for others, only one test may be specified.It should be noted that not all of the above tests are required to establish the resistance spot welding behavior of a givengr
46、ade of steel. The current level/current range testing and weld property testing together generally provide a good indica-tion of the resistance spot welding behavior, whereas the DoE testing is intended to examine the robustness of a givengrade of high strength steel to variations in key process var
47、iables. The specific tests required to establish the resistancespot welding behavior of a given grade of steel should be agreed upon by the steel supplier (or test laboratory) and theautomotive company (or buyer of the steel).Users of this document have requested that subsequent updates to the docum
48、ent include provisions for the incorporationof other types of welding equipment, electrode caps, and weld schedules than those provided in the document. The inclu-sion of these alternative methods may permit the testing to be more customer-focused and allow for the determination ofspecific material
49、and welding performance issues as they relate to a particular manufacturing situation. A commentaryand discussion are provided in Annex E and are intended to serve as guidelines should the users of this document desireto utilize alternative test methods for the weld characterization of sheet steels.It should be noted that, as the weldability evaluation procedures in alternative methods deviate from the proceduredescribed in this document, they may add to the complexity and cost of the material evaluation. The type of evaluationsrequired, and any deviations required to perform them, should
