ANSI AWS D8.7M-2005 Recommended Practices for Automotive Weld Quality Resistance SpotWelding.pdf

1、RecommendedPractices forAutomotiveWeld QualityResistanceSpot WeldingAWS D8.7M:2005An American National StandardReproduced by Global Engineering Documents With the Permission of AWS Under Royalty Agreement 550 N.W. LeJeune Road, Miami, Florida 33126AWS D8.7M:2005An American National StandardApproved

2、byAmerican National Standards InstituteDecember 9, 2004Recommended Practices forAutomotive Weld QualityResistance Spot WeldingSupersedes ANSI/AWS D8.7-88RPrepared byAWS D8 Committee on Automotive WeldingUnder the Direction ofAWS Technical Activities CommitteeApproved byAWS Board of DirectorsAbstract

3、This document presents recommended practices and criteria for evaluating resistance spot welds typical of automotivesheet steel applications. The document contains weld characteristics, metrics and testing methods useful in evaluatingspot welding quality on coated and uncoated automotive sheet steel

4、s of all strength levels and compositions. The testmethods described are designed to assess both static and dynamic properties of automotive sheet steel welds.Key WordsResistance spot welding, weld quality, destructive test, nondestructive testStatement on Use of AWS American National StandardsAll s

5、tandards (codes, specifications, recommended 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 standards are either

6、 incorporated in, or made part of,documents that are included in federal or state 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 beapproved by the governmenta

7、l body having statutory jurisdiction before they can become a part of those laws andregulations. In all cases, these standards carry the full legal authority of the contract or other document that invokes theAWS standards. Where this contractual relationship exists, changes in or deviations from req

8、uirements of an AWSstandard must be by agreement between the contracting parties.International Standard Book Number: 0-87171-732-8American Welding Society, 550 N.W. LeJeune Road, Miami, FL 33126 2004 by American Welding Society. All rights reservedPrinted in the United States of AmericaAWS American

9、National Standards are developed through a consensus standards development process that bringstogether volunteers representing varied viewpoints and interests to achieve consensus. While AWS administers the processand establishes rules to promote fairness in the development of consensus, it does not

10、 independently test, evaluate, orverify 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 spe-cial, indirect, consequential or compensatory,

11、 directly or indirectly resulting from the publication, use of, or reliance on thisstandard. 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 o

12、ther services for or onbehalf 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 judgment or, as appropriate, seek the adviceof a competent professional in determining

13、 the exercise of reasonable care in any given circumstances.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 acceptan

14、y and all liabilities for infringement of any patent or trade name items. AWS disclaims liability for the infringement ofany patent or product trade name resulting from the use of this standard.Finally, AWS does not monitor, police, or enforce compliance with this standard, nor does it have the powe

15、r to do so.On occasion, text, tables, or figures are printed incorrectly, constituting errata. 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 writ-i

16、ng, to the Managing Director, Technical Services Division, American Welding Society, 550 N.W. LeJeune Road, Miami, FL33126 (see Annex A). With regard to technical inquiries made concerning AWS standards, oral opinions on AWS standardsmay be rendered. However, such opinions represent only the persona

17、l opinions of the particular individuals giving them. Theseindividuals do not speak on behalf of AWS, nor do these oral opinions constitute official or unofficial opinions or interpreta-tions of AWS. In addition, oral opinions are informal and should not be used as a substitute for an official inter

18、pretation.This standard is subject to revision at any time by the AWSD8 Committee on Automotive Welding. It must be reviewedevery 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

19、 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 of the comments will be informed of the Committees response to the comments. Guests areinvited to attend all

20、meetings of the AWS D8 Committee on Automotive Welding to express their comments verbally.Procedures for appeal of an adverse decision concerning all such comments are provided in the Rules of Operation ofthe Technical Activities Committee. A copy of these Rules can be obtained from the American Wel

21、ding Society, 550N.W. LeJeune Road, Miami, FL 33126.Photocopy RightsAuthorization to photocopy items for internal, personal, or educational classroom use only, or the internal, personal, oreducational classroom use only of specific clients, is granted by the American Welding Society (AWS) provided t

22、hat theappropriate fee is paid to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, Tel: 978-750-8400;online: http:/.iiiPersonnelAWS D8 Committee on Automotive WeldingJ. C. Bohr, Chair General Motors North AmericaW. H. Brafford, 1st Vice Chair Tuffaloy ProductsD. R. Kolodziej, 2

23、nd Vice Chair Ford Motor CompanyH. P. Ellison, Secretary American Welding SocietyT. Anderson AlcoTec Wire CorporationG. Armstrong Inmet Division of MultimaticJ. Dolfi Consultant*J. F. Hinrichs Friction Stir Link, IncorporatedT. W. Morrissett ConsultantJ. S. Noruk Servo Robot CorporationJ. P. Osborne

24、 DeStaCo IndustriesAWS D8D Subcommittee on Automotive Resistance Spot WeldingJ. C. Bohr, Chair General Motors North AmericaW. Qualls, 1st Vice Chair ConsultantH. Zhang, 2nd Vice Chair University of ToledoH. P. Ellison, Secretary American Welding SocietyW. H. Brafford Tuffaloy ProductsM. Kimchi Ediso

25、n Welding InstituteV. Klein LTK Engineering ServicesT. W. Morrissett ConsultantT. V. Natale AK SteelC. J. Orsette RoMan Engineering Services, IncorporatedJ. P. Osborne DeStaCo IndustriesN. S. Scotchmer Huys IndustriesT. Sparschu Candid Logic/Craft LineD. J. Walker Centerline (Windsor) LimitedAWS Tas

26、k Force for Document Preparation and RevisionJ. Bohr, Chairman General Motors North AmericaH. Zhang University of Toledo*AdvisorAWS D8.7M:2005This page is intentionally blank.ivAWS D8.7M:2005vForeword(This Foreword is not a part of AWS D8.7M:2005, Recommended Practices for Automotive WeldQualityResi

27、stance Spot Welding, but is included for informational purposes only.)This document has been prepared as an informative reference to recognize a consensus of practices that may assistautomotive industry suppliers in their understanding of resistance spot weld criterion and the methods for assessment

28、 ofweld quality. As a recommended practice the criteria and techniques contained are not obligatory until cited as a normativereference in a mandatory document.This recommended practice was prepared by the AWS D8D Subcommittee on Automotive Resistance Spot Weldingof the AWS D8 Committee on Automotiv

29、e Welding. This publication is issued under the auspices of the AWS D8Committee on Automotive Welding.The present publication of Recommended Practices for Automotive Weld QualityResistance Spot Welding is anupdate of the original document published in 1978. This edition presents an extension of prev

30、ious information alongwith an introduction of new data and test methodologies. These enhancements are based on research activities sponsoredby resistance welding equipment manufacturers, steel companies, automotive manufacturers, universities and the UnitedStates Department of Commerce.Comments and

31、suggestions for the improvement of this standard are welcome. They should be sent to the Secretary,AWS D8 Committee on Automotive Welding, American Welding Society, 550 N.W. LeJeune Road, Miami, FL 33126.Official interpretations of any of the technical requirements of this standard may only be obtai

32、ned by sending arequest, in writing, to the Managing Director, Technical Services Division, American Welding Society. A formal replywill be issued after it has been reviewed by the appropriate personnel following established procedures.AWS D8.7M:2005This page is intentionally blank.viAWS D8.7M:2005v

33、iiTable of ContentsPage No.Personnel iiiForeword vList of Tables viiiList of Figures. viii1. Scope .12. Normative Reference.13. Terms and Definition 14. General 24.1 Weld Process Control 24.2 Satisfactory Weld.24.3 Material Limitations 24.4 Surface Condition 24.5 Weld Through Sealers and Adhesives.2

34、4.6 Part Fit-Up .24.7 Weld Identification 25. Weld Quality Evaluation Criteria25.1 Size 25.2 Location .35.3 Spacing 35.4 Indentation .35.5 Distortion .35.6 Weld Appearance.35.7 Quantity .35.8 Penetration .36. Inspection Techniques.56.1 Visual Evaluation.56.2 Nondestructive Testing56.3 Destructive Te

35、sting67. Test Methods.67.1 Peel Test.67.2 Chisel Test .67.3 Metallographic Test.67.4 Tensile-Shear Test .67.5 Double Pendulum Impact Test 67.6 Other Tests.98. Disposition of Substandard Products 9AWS D8.7M:2005viiiPage No.9. Safety.9Nonmandatory Annexes13Annex AGuidelines for Preparation of Technica

36、l Inquiries for AWS Technical Committees 13Annex BReference Documents 15List of AWS Documents on Automotive Welding17AWS D8.7M:2005ixList of TablesTable Page No.1 Weld Sizes for Automotive Resistance Spot Welding.22 Minimum Width for Tensile-Shear Testing Specimens 63 Minimum Width for Impact Testin

37、g Specimens6List of FiguresFigure Page No.1 Measurement of Weld Size 32 Attributes of a Spot Weld Measured from a Section Through the Center.33 An Edge Weld44 A Mislocated Weld 45 Overlapped Welds46 Potentially Insufficient Spaced Welds .47 Excessive Indentation 48 Weld Distortion59 Holes and Whiske

38、rs on a Weld Surface.510 Surface Cracks .511 Impact Testing Specimen Dimensions.712 Peel Test.713 Chisel Test814 Porosity in a Weld Revealed in a Cross Section815 Tensile-Shear Test816 Quantities to be Measured in a Tensile-Shear Test917 Tensile-Shear Test Failure Mode.1018 Double Pendulum Impact Te

39、st.11AWS D8.7M:2005This page is intentionally blank.xAWS D8.7M:2005AWS D8.7M:200511. ScopeThis recommended practice expresses an industryconsensus of quality characteristics and metrics pertinentto resistance spot welds on automotive materials. Thesubject matter is considered to be realistic and tem

40、peredwith the knowledge of what a resistance spot weldingprocess is capable of accomplishing in a high volumeproduction environment. The criteria and metrics are thesame for all welds regardless of service load andintended to be applied in conditions typically encoun-tered during manufacturing. Weld

41、s at variance from thestated criteria can have mechanical properties that satisfyproduct and design requirements. Any attempted appli-cation of this document or the evaluation criteria usedherein to other uses, as for example post-crash weldquality assessment, may lead to an erroneous result.This st

42、andard makes sole use of the InternationalSystem of Units (SI).2. Normative ReferenceThe following standard contains provisions which,through reference in this text, constitute provisions ofthis AWS standard. For undated references, the latestedition of the referenced standard shall apply. For dated

43、references, subsequent amendments to, or revisions ofthis publication do not apply.AWS A3.0:2001, Standard Welding Terms andDefinitions.Applications for copies should be addressed to GlobalEngineering Documents, 15 Inverness Way East, Engle-wood, Co 80112-5776, tel: 800-854-7179, website:.3. Terms a

44、nd DefinitionsThe terms listed are used in various sections of thisdocument and require definition for correct interpre-tation. Most of these terms are not contained in AWSA3.0-2001, Standard Welding Terms and Definitions, orif they are listed in AWS A3.0, their definitions havebeen enhanced to clar

45、ify their use in this document.adjacent welds. Welds located next to each other joiningthe same pieces of metal.coupon. A single, small piece of test material with speci-fied dimensions that is used to make up test samples.edge weld. A weld located such that the electrode con-tact area as indicated

46、by the weld indentation overlapsthe edge of the sheet.Governing Metal Thickness (GMT). The GMT for atwo-sheet stackup is the metal thickness of the thinnerof the two sheets. The GMT for a three-sheet stackupis the metal thickness of the second thickest sheet.minimum weld size. The smallest allowable

47、 value fornugget width or the weld button.minimum weld spacing. Minimum weld spacing is theshortest permissible distance or pitch from weld cen-ter to weld center of adjacent welds.partial interfacial fracture. A fracture mode of a spotweld where a part of the weld nugget (fused area of aspot weld)

48、separates through the plane of the weld andsome portion of the weld pulls out as a partial button.penetration. The height of the fusion zone expressed asa percent of the total material stack up welded.set-up weld size. The set-up weld size is the weld size tobe obtained during equipment set-up and w

49、hen theelectrodes are new.weld aspect ratio. The weld aspect ratio is the ratio ofthe maximum diameter measurement to the minimumdiameter measurement of the weld button.weld group. A weld group is a row, string, pattern, or anarray of spot welds joining one part to another. Weldgroupings are identified on the product drawing.Recommended Practices for AutomotiveWeld QualityResistance Spot WeldingAWS D8.7M:200524. General4.1 Weld Process Control. Production welded parts thatare joined by the resistance spot welding process havecontinually changing weld q