1、 WORLDWIDE ENGINEERING STANDARDS Material Specification GMW14056 Weld Acceptance Criteria and Repair Procedures Drawn-Arc Welded Automotive Studs, Nuts and Brackets Copyright 2013 General Motors Company All Rights Reserved December 2013 Page 1 of 8 1 Scope Note: Nothing in this standard supercedes a
2、pplicable laws and regulations. Note: In the event of conflict between the English and domestic language, the English language shall take precedence. 1.1 Purpose. This standard provides the weld acceptance criteria and repair procedures for evaluating drawn-arc welded studs, nuts and brackets in aut
3、omotive products for which GM is responsible for establishing or approving the product design. 1.2 Applicability. The criteria established in this standard become mandatory when referenced on a weld design document. Deviation from any weld criteria provided in this standard must be identified on a w
4、eld design document. 1.3 Usage. Welded structures are considered satisfactory when they meet the expected design service loads and satisfy functional performance requirements. The evaluation criteria contained in this document has been established as a basis for the manufacturing acceptance of welde
5、d products and are the same for all welds regardless of service load. Furthermore, welds identified as discrepant often retain a percentage of their mechanical properties and may contribute to the integrity of the welded product. Application of this specification for other uses, such as post-crash w
6、eld quality assessment, may lead to erroneous results or conclusions. 1.4 Clarification. For clarification of this specification or editorial comments, email the GM Weld Council at . 2 References Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 External Standar
7、ds/Specifications. None 2.2 GM Standards/Specifications. GMN3903 GMW14058 GMW15563 3 Requirements 3.1 General Acceptance Criteria. Not applicable. 3.2 Visual Acceptance Criteria. 3.2.1 Spatter. A drawn-arc welded fastener with weld spatter on its threaded section that interferes with the mating fast
8、ener is discrepant. 3.2.2 Weld Eruption. A drawn-arc welded fastener with weld eruption that interferes with the installation of the mating part is discrepant. See Figure A1. 3.2.3 Missing Fastener. A drawn-arc welded fastener that is missing is discrepant. 3.2.4 Cracks. A drawn-arc welded fastener
9、shall be free from detectable surface cracks that are visible (without the aid of magnification) within or adjacent to the weld. Welded fasteners exhibiting cracks are discrepant. 3.2.5 Holes. A drawn-arc welded fastener that contains holes or burn-throughs in either the fastener or mating part is d
10、iscrepant. 3.3 Measurable Acceptance Criteria. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14056 Copyright 2013 General Motors Compan
11、y All Rights Reserved December 2013 Page 2 of 8 3.3.1 Fastener Location. A drawn-arc welded fastener positioned outside of the location tolerance specified on the weld design document is discrepant. When no location tolerance is specified, a stud or bracket fastener greater than 2 mm from the indica
12、ted design location is discrepant. When no location tolerance is specified, a nut fastener greater than 1 mm from the indicated design location is discrepant. 3.3.2 Fusion of Weldable Area. A drawn-arc welded fastener that does not indicate a minimum of 75% of the weldable area with fusion to the ma
13、ting part is discrepant. See Figure A4 and Figure A6. 3.3.3 Measurement of Fusion. 3.3.3.1 Drawn-Arc Studs. Fusion can be measured by destructive testing. When a stud is separated from its mating part by a tensile load or by an oscillating side-to-side motion (see Figure A7), a weld button will be p
14、ulled either on the head of the stud or on the mating part. See Figure A2. When destructive testing, if the stem of the weld stud separates from the weld stud head, the fusion is considered acceptable. 3.3.3.2 Drawn-Arc Nuts. Fusion can be measured by destructive testing. When a nut is separated fro
15、m its mating part by a tensile load or by an oscillating side-to-side motion (see Figure A7), a weld button will be pulled either on the base of the nut or on the mating part. See Figure A6. 3.3.3.3 Drawn-Arc Brackets. Fusion can be measured by destructive testing. When a bracket is separated from i
16、ts mating part by a tensile load or by an oscillating side-to-side motion (see Figure A7), a weld button will be pulled either on the bracket itself or on the mating part. See Figure A2 and Figure A6. 3.3.4 Reduction in Weld Stem Size. A stud whose stem diameter is reduced by greater than 10% as a r
17、esult of the welding process is discrepant. See Figure A5. 3.3.5 Functional Height for T Stud. T studs that do not satisfy the functional height requirements of the mating part are discrepant. See Figure A5. 3.3.6 Nondestructive Testing. A nondestructive test (proof-load) of the fasteners may be use
18、d to judge acceptability provided that a Measure of Agreement Study has been conducted and approved by the local Quality Department. 3.4 Disposition/Repair Procedure. 3.4.1 Drawn-Arc Welded Fastener Repair Requirements. All known discrepant welded fasteners shall be repaired. 3.4.2 Repair Procedures
19、. Drawn-arc welded fasteners shall be repaired according to the repair procedures shown in Appendix B, unless other repair procedures are specifically indicated and authorized by the appropriate Product Engineer. 4 Manufacturing Process 4.1 Process Control. The welding source is responsible for esta
20、blishing practices and test methods to assure that the criteria of this standard are met, and are consistent with GMW15563, Joining and Dispense Process Control Procedure. 5 Notes 5.1 Glossary. Crack: A fracture type discontinuity characterized by a sharp tip and high ratio (length to width) of the
21、opening displacement on the exterior surface. Fastener: For the purpose of this standard, a drawn-arc welded stud, nut or bracket is referred to as a fastener. Fusion: The melting together of a fastener and the base metal to produce a weld. Measure of Agreement Study: An Engineering study that demon
22、strates that the nondestructive load applied is in excess of a load that would meet the minimum acceptable criteria of this standard but not destroy or distort the parts being tested. The Engineering study demonstrates that there is a relationship between load applied (torque, tensile, push-out, etc
23、.) and the minimum acceptable criteria of this standard. This relationship is usually established by measuring the applied load (to failure) over an expected range of welding variables. T Stud: An abbreviation for trim stud. See Figure A3 and Figure A5. Weld Button: That part of the weld that tears
24、out in the destructive testing of the welded fastener. See Figure A2 and Figure A6. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14056
25、 Copyright 2013 General Motors Company All Rights Reserved December 2013 Page 3 of 8 Weld Design Document: A product document that describes welding requirements such as number of welds, location of welds, applicable weld standards, weld patterns, surface appearance classification, weld notes, etc.
26、This document is released and approved by the appropriate Design Release Engineer. Weld Eruption: Material that flows around and/or above the head of the stud as a result of the welding process. See Figure A1. Weld Spatter: Weld expulsion metal that remains attached to an adjacent metal surface. Wel
27、d Stud Head: That part of the weld stud that is fused to the mating part. See Figure A3. Weld Stud Stem: That part of the weld stud that engages a mating part. See Figure A3. 5.2 Acronyms, Abbreviations, and Symbols. GMAW Gas Metal Arc Welding 6 Coding System This standard shall be referenced in oth
28、er documents, drawings, etc., as follows: GMW14056 7 Release and Revisions This standard was originated in August 2004. It was first approved by the CCRW Global Council in August 2005. It was first published in August 2005. Issue Publication Date Description (Organization) 1 AUG 2005 Initial publica
29、tion. 2 APR 2012 Update usage, references and template. Add reference to GMW15563 for process control. Remove limitation to steel. (GM Global Weld Council) 3 DEC 2013 Revised title to remove limitation to steel. Updated standards referenced, GME7834 removed. (GM Global Weld Council) Copyright Genera
30、l Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14056 Copyright 2013 General Motors Company All Rights Reserved December 2013 Page 4 of 8 Appendix A Figu
31、re A1: Weld Eruption Figure A2: Weld Button Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14056 Copyright 2013 General Motors Company A
32、ll Rights Reserved December 2013 Page 5 of 8 Figure A3: Typical Drawn-Arc Welded Studs Figure A4: Weldable Area Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE EN
33、GINEERING STANDARDS GMW14056 Copyright 2013 General Motors Company All Rights Reserved December 2013 Page 6 of 8 Figure A5: Stem Diameter Reduction (d) and Height (h) Measurements for a T Stud Figure A6: Fused Weld Area of a Drawn-Arc Weld Nut Copyright General Motors Company Provided by IHS under l
34、icense with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14056 Copyright 2013 General Motors Company All Rights Reserved December 2013 Page 7 of 8 Figure A7: Destruction by Oscillating Side-to-Side Moti
35、on Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14056 Copyright 2013 General Motors Company All Rights Reserved December 2013 Page 8 o
36、f 8 Appendix B Table B1: Drawn-Arc Welded Fastener Repair Procedures Discrepant Condition Description GMW14056 Reference Repair Procedure Spatter Fasteners that exhibit spatter in the threaded section of the fastener that interferes with the mating fastener. 3.2.1 Wire brush (for studs) or clean thr
37、eads with a tap (for nuts) to remove spatter. Missing fastener Note 1 Fastener not installed. 3.2.3 Reprocess part and install drawn-arc welded fastener or Studs and Nuts: Add two Gas Metal Arc Welding (GMAW) fillet welds Note 2, Note 3 each covering a minimum of 90 of the circumference and opposite
38、 each other. Brackets: Add one GMAW fillet weld Note 2, Note 3 for a minimum of 75% of the length of the weldable area. or Studs: Install a rivet style stud as specified by Product Engineering. Drill a hole as specified by the rivet style stud manufacturer and install using the manufacturers approve
39、d tool. Cracks or holes Note 1 Cracks or holes are present. 3.2.4 3.2.5 GMAW Note 2, Note 3 so that the discrepant condition is no longer present. Weld eruption Note 1 A welded stud with weld metal that interferes with the installation of the mating part. 3.2.2 Grind to remove discrepant condition o
40、r follow appropriate repair method for mislocated fastener. Mislocated fastener Note 1 The fastener is located outside the position tolerance. 3.3.1 Remove the mislocated fastener and grind as necessary to restore mating surface. Follow appropriate repair method for missing fastener. Insufficient we
41、ld size Note 1 Fusion is less than 75% of weldable area. 3.3.2 Studs and Nuts: Add two GMAW fillet welds Note 2, Note 3 each covering a minimum of 90 of the circumference and opposite each other. Brackets: Add one GMAW fillet weld Note 2, Note 3 for a minimum of 75% of the length of the weldable are
42、a. Reduced weld stem size Note 1 Stud stem diameter is reduced by greater than 10%. 3.3.4 Remove the fastener and grind as necessary to restore mating surface. Follow appropriate repair method for missing fastener. Functional height Note 1 T stud does not satisfy the functional height requirements o
43、f the mating part. 3.3.5 Remove the fastener and grind as necessary to restore mating surface. Follow appropriate repair method for missing fastener. Note 1: If part is painted and to be repaired by welding, prepare fastener location by grinding to remove paint where fastener will be installed and r
44、epaint after repair. Note 2: Repair welds must meet applicable GM acceptance criteria (i.e., GMW14058, GMN3903). Note 3: Applications of steel sheet thinner than 1.2 mm or laminated steel shall use Arc Brazing for repair welds. Arc Braze repair welds shall meet applicable GM acceptance criteria (i.e., GMW14058). Do not use steel wire for these applications. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
