1、WORLDWIDEENGINEERINGSTANDARDSMaterial Specification GMW16056Bumper Quality Steel Sheet for Decorative Plating or Painting Copyright 2012 General Motors Company All Rights ReservedOctober 2012 Originating Department: North American Engineering Standards Page 1 of 41 ScopeNote: Nothing in this standar
2、d supercedes applicable laws and regulations.Note: In the event of conflict between the English and domestic language, the English language shall takeprecedence.1.1 Material Description. This specification covers surface requirements for hot rolled (HR) or cold rolled (CR)sheet steel that is to be e
3、lectroplated with nickel and chromium or painted for decorative purposes.1.2 Symbols. Not applicable.1.3 Typical Applications. Decorative nickel-chromium plated or painted steel is often used for truck bumpers.1.4 Remarks. For general requirements regarding plating, GMW14672 requirements must be met
4、.2 ReferencesNote: Only the latest approved standards are applicable unless otherwise specified.2.1 External Standards/Specifications.ASTM E112 SAE J9112.2 GM Standards/Specifications.GMW2 GMW11 GMW3059 GMW14672GMW8 GMW3032 GMW32242.3 Additional References.TMC003 Material Safety Data Sheet guidance
5、documents (available at ).3 Requirements3.1 Requirements on Test Specimens. All decorative plating requirements for this specification may be meteither by mill rolling practice (Type A) or by polishing of steel coils or blanks (Type B). Type B finish is requiredfor chrome plating of hot rolled steel
6、, and is typically used for cold rolled steel. Steel used for exposed, paintedbumpers shall meet the Type C finish requirements.Steels covered by this specification may be any of those listed in and approved to GMW2 and GMW3032.3.2 Mechanical Properties. Steels must meet the minimum 0.2% offset yiel
7、d strength and tensile strengthmechanical property requirements in GMW2 (low carbon HR or CR grades) or GMW3032 (Low Alloy (LA),Bake Hardenable with 2% pre-strain (B2) or Re-phosphorized (P) grades). Additionally, temper rolling isrequired in order to eliminate Yield Point Elongation (Lders Lines) i
8、n the formed product. Therefore, themaximum yield strength requirement will be waived. The minimum elongation and minimum n-value shall benegotiated between the steel supplier and the bumper manufacturer.3.3 Grain Size. The grain size shall meet the following requirements based on the specified subs
9、trate:GMW2: Must meet the grain size requirements for GMW2 HR and CR substrates.GMW3032: Must meet the grain size requirements for GMW3032 HR and CR substrates.All grain size measurements shall be done in accordance with ASTM E112.Note: For best surface appearance after forming, steels of at least 2
10、40 MPa yield strength are recommended.3.4 Appearance. Stamped steel surfaces that are decorative plated or painted must be capable of meetingpart appearance requirements as defined by a master sample. Decorative plated bumpers shall meet thespecified standard as agreed between purchaser and supplier
11、, once plated per GMW14672 requirements.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 GMW16056 Copyright 2012 General Motors Company All R
12、ights ReservedOctober 2012 Page 2 of 4Post-forming metal finishing may be used on selected surfaces to meet appearance or corrosion requirementsfor decorative plated bumpers.3.5 Surface Quality. Surface shall be free of pits, laminations, inclusions, pickups, or other defects which mayaffect appeara
13、nce, durability, or function, once plated in accordance with GMW14672 or painted and asagreed between supplier and purchaser.3.5.1 Bumper quality steel furnished to this standard shall utilize temper rolled steel to sufficiently eliminatestretcher strain (Lders Lines) in the formed bumper product, d
14、enoted by the “T” surface finish in thespecification callout (see Section 8). Use of bumper quality steel does not necessarily preclude the need forpost-forming/pre-plating or painting metal finish in local areas to meet appearance requirements.3.6 Surface Finish. Measurements per SAE J911.3.6.1 Dec
15、orative Plated Bumper Steel. If type of finish (A or B) is not specified, Type A shall be assumed.3.6.1.1 Type A (Mill Finish). All temper rolled steel supplied under this specification shall have the followingsurface finish: Ra 0.9 microns (35 micro in) maximum, and Rm 80 microns (300 micro in) max
16、imum.3.6.1.2 Type B (Flat Polished). Steel blanks shall be finished using a combination dry and wet abrasive beltsequence to Ra 0.3 microns (12 micro in) maximum and Rm 3 microns (118 micro in) maximum, prior toforming. To allow for metal removal in flat polishing, the upper tolerance limit per GMW3
17、224 is increased by0.07 mm.3.6.2 Painted Bumper Steel.3.6.2.1 Type C (Painted Bumpers). Cold rolled or hot rolled steel shall be capable of being painted to meetfinished part quality requirements. The surface finish of steel to be used for painted bumpers shall meet theType A mill finish requirement
18、s: Ra 0.9 microns (35 micro in) maximum, and Rm 80 microns (300 micro in)maximum.3.6.2.1.1 Coating Requirements. Refer to coating requirements in GMW8 for hot dipped coatings andGMW11 for electro galvanized coatings, if applicable. Coating requirements include, but are not limited tocoating composit
19、ion, coating mass, and coating adhesion.4 Manufacturing ProcessNot applicable.5 Rules and Regulations5.1 Legal Regulations. All materials must satisfy applicable laws, rules, regulations and recommendationsvalid in the country of usage.5.2 Language. In the event of conflict between the English and d
20、omestic language, the English language shalltake precedence.5.3 Inspection and Rejection. Samples of components or materials released to a GM material specificationshall be tested for conformity with the requirements of this material specification and approved by theresponsible Engineering departmen
21、t prior to commencement of delivery of bulk supplies.A new approval must be received for any changes, e.g., properties, manufacturing process, location ofmanufacture, etc. If not otherwise agreed, all testing and documentation normally required for initial releasemust be completed.It is the responsi
22、bility of the supplier to inform the customer in a timely manner, without solicitation, and toinclude documentation of all modifications of materials and/or processes and to apply for a new release.If not otherwise agreed, all release tests shall be repeated and documented by the supplier prior toco
23、mmencement of delivery of non-conforming bulk supplies. In individual cases, a shorter test can be agreedto between the responsible Engineering department and the supplier.5.4 Material Safety Data Sheets/Safety Data Sheets (MSDS/SDS). For new product submissions, or when achange in chemical composit
24、ion of an existing product has occurred, a complete copy of the Material SafetyData Sheet/Safety Data Sheet must be submitted in compliance with the Globally Harmonized System ofClassification and Labeling of Chemicals (GHS) requirements or other country-specific MSDS/SDSrequirements. In addition, p
25、roduct MSDS/SDS submissions must be in compliance with specific countryGeneral Motors TMC003 Material Safety Data Sheet/Safety Data Sheet guidance documents where available.Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or netw
26、orking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16056 Copyright 2012 General Motors Company All Rights ReservedOctober 2012 Page 3 of 45.5 All materials supplied to this standard must comply with the requirements of GMW3059, Restricted andReportable Substances for
27、 Parts.6 Approved SourcesMaterials supplied to this specification must be approved by General Motors.The appropriate GM Materials Engineering department(s) must confirm material as meeting the requirementsof this specification. Any test data sheets of material submitted to General Motors for such co
28、nfirmation (e.g.,during Production Part Approval Process (PPAP) under this material specification must list all properties andmust apply corresponding test methods of this material specification.7 Notes7.1 Glossary.7.2 Acronyms, Abbreviations, and Symbols.B2 Bake Hardenable (with 2% pre-strain)CR Co
29、ld RolledGHS Globally Harmonized System of Classification and Labeling of ChemicalsHR Hot RolledLA Low AlloyMSDS Material Safety Data SheetP Re-phosphorizedPPAP Production Part Approval ProcessSDS Safety Data Sheet8 Coding SystemThis standard shall be referenced in other documents, drawings, etc., a
30、s follows:The substrate steel properties shall conform to requirements as defined under Section 3. Galvanized steel forpainted bumpers shall meet the coating requirements in GMW8 or GMW11.8.1 Material per GMW16056-Type B-CR240LA-UNCOATED-T. This is a nickel-chromium plated bumper thatis made of cold
31、 rolled or hot rolled uncoated and temper rolled bumper quality steel with a Type B surfacefinish (flat polished, see 3.6.1.2).The coding details are as follows:GMW16056-Type B-CR240LA-UNCOATED-TWhere:GMW16056 = Nickel-Chromium Plated Bumper specificationType B = Surface Finish (Flat-Polished)CR = S
32、teel Product Type: Cold rolled240 = 240 MPa minimum. Yield strength grade (see GMW3032)LA = High Strength Low Alloy grade (Steel Type, see 3.2)UNCOATED = Uncoated surface designationT = Temper rolled surface condition (see 3.5)Copyright General Motors Company Provided by IHS under license with Gener
33、al Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16056 Copyright 2012 General Motors Company All Rights ReservedOctober 2012 Page 4 of 48.2 Material per GMW16056-Type C-CR240LA-HD60G60G-T. This is for a painted
34、bumper that is made ofcold rolled or hot rolled hot dipped galvanized and temper rolled steel with the required surface finish.The coding details are as follows:GMW16056-Type C-CR240LA-HD60G60G-TWhere:GMW16056 = Nickel-Chromium Plated Bumper specificationType C = Surface Finish (Painted Bumpers)CR =
35、 Steel Product Type: Cold rolled240 = 240 MPa minimum. Yield strength grade (see GMW3032)LA = High Strength Low Alloy grade (Steel Type, see 3.2)HD60G60G = Hot Dipped Galvanized Coating Designation (see GMW8)T = Temper rolled surface condition (see 3.5)9 Release and RevisionsThis standard was origin
36、ated in September 2008. It was first approved by Materials in April 2009. It was firstpublished in April 2009.Issue Publication Date Description (Organization)1 APR 2009 Initial publication.2 NOV 2010 Revised publication. (Global Ferrous and Sheet Metal Team) Changes are asfollows:1.1 Added Painted
37、bumpers to the specification.1.3 Added exposed and painted bumpers to the typical applications.3.1 Clarified decorative plating requirements and added Type C finish forbumpers.3.2 Detailed mechanical property requirements. Waived maximum yield strengthrequirement.3.3 Detailed grain size requirements
38、 for various steel grades used for bumperapplications. Change recommended strength level for bumper grades to240 MPa or higher yield strength steel grades.3.4 Further defined appearance requirement.3.5 Added painted bumper and surface quality requirements to this section.3.6.1.1 Increased requiremen
39、ts: Ra 0.9 microns (35 micro in).3.6.1.2 Type B tolerance increased to 0.07 mm.3.6.2 Painted Bumper steel requirements added.8.0 Detailed example added to the coding system.3 OCT 2012 2.2 (new references), 3.4, 3.5.1 (new section), 3.6.1.1, 3.6.2.1, 3.6.2.1.1 (Newsection for coatings), 3.6.3 (deleted), 3.7 (deleted), Section 8 (callout examples).(Ferrous Metals and Sheet GSSLT)Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
