1、WORLDWIDEENGINEERINGSTANDARDSGeneral Specification GMW14670Organic Coat Finish for Steel Wheels Copyright 2012 General Motors Company All Rights ReservedNovember 2012 Originating Department: GME Specification Center Page 1 of 51 IntroductionNote: Nothing in this standard supercedes applicable laws a
2、nd regulations.Note: In the event of conflict between the English and domestic language, the English language shall takeprecedence.1.1 Scope. Organic coat finishes which ensure adequate protection against corrosion on surfaces of road steelwheels.Note: Some sections reference both, GMW Test Procedur
3、es and local Test Procedures. As soon as the GMWis available, it supercedes the local test method.1.2 Mission/Theme. This standard describes the properties of organic coat finishes which ensure adequateprotection against corrosion on surfaces of painted steel wheels. The wheels shall be coated with
4、approvedmaterials. Approved materials are identified in the MATSPC database under 998XXXX-numbers (e.g. 9984120epoxy elpo).Suitable systems may include the following:1.2.1 Single Coat System. Cathodic electrodeposition primer (epoxy or acrylic ELPO).Spare wheels and wheels that are fully covered ( 9
5、0 %) can be painted by epoxy elpo. Acrylic elpo should befor wheels that are not fully covered and for this reason need higher UV-resistance.1.2.2 Multi-coat Systems. Double or multi coat systems (e.g. elpo and top coat or elpo, base coat and clearcoat).The clear coat (powder or wet coat) shall be r
6、esistant against, weathering and chemicals.Acrylic paint for example is suitable.Note: The colored paint coat and the top coat (clear coat) of any multi-coat system when required need onlybe applied to significant and/or visible surfaces as shown on the relevant engineering drawing e. g. the discout
7、er, spoke recess and rim flange.Note: The specific composition of the organic coat finish is not a part of the standard, however pre-treatment,paint system and minimum film thickness of the organic coat finish shall be confirmed by the supplier in writingand are part of the initial sample approval.T
8、he relevant suppliers as well as their material designations of the used pre-treatments and materials shall becommunicated.1.3 Classification.1.3.1 Type A. Single Coat System epoxy elpo black (only wheels which are fully covered or spare wheels).1.3.2 Type B. Single Coat System acrylic elpo black.1.
9、3.3 Type C. Double Coat System (elpo, topcoat). Double-layer types are only permissible for inflatable sparetires.1.3.4 Type D. Multi Coat System (e.g. elpo, base coat, clear coat).2 ReferencesNote: Only the latest approved standards are applicable unless otherwise specified.2.1 External Standards/S
10、pecifications.SAE J1960 SAE J2527Copyright 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 GMW14670 Copyright 2012 General Motors Company All Rights R
11、eservedNovember 2012 Page 2 of 52.2 GM Standards/Specifications.GMW3059 GMW14698 GMW14829 GMW15282GMW3286 GMW14700 GMW14872 GMW15288GMW14333 GMW14701 GMW14873GMW14334 GMW14704 GMW152723 Test Preparation and Evaluation3.1 Resources.3.1.1 Calibration. The test facilities and equipment shall be in good
12、 working order and shall have a validcalibration label.3.1.2 Alternatives. Alternative test facilities and equipment may also be used. However, all measuringvariables as specified in this standard shall be determined correctly with respect to their physical definition.3.1.3 Facilities. Apparatus as
13、required by the appropriate test method.3.1.4 Equipment. Equipment suitable for measuring coating thicknesses based on eddy current orferromagnetic principles having an accuracy of 2.0 m.3.1.5 Test Vehicle/Test Piece. Test pieces, shape, dimensions and number of test pieces as specified in theapprop
14、riate test method.3.1.6 Test Time. According to the appropriate test method.3.1.7 Test Required Information. According to the appropriate test method.3.1.8 Personnel/Skills. According to the appropriate test method.3.2 Preparation. Tests according to paragraphs 4.3.7 thru 4.3.11 are only applicable
15、for the disc outer.If test pieces cannot be prepared due to wheel dimensions for the relevant tests, the supplier shall deliverspecial test samples with the original substrate (material) in dependence of the test but the original coat in anycase.3.3 Conditions.3.3.1 Environmental Conditions. Accordi
16、ng to the appropriate test method.3.3.2 Test Conditions. Deviations from the requirements of this standard shall have been agreed upon. Suchrequirements shall be specified on component drawings, test certificates, reports, etc.3.4 Instructions. Not applicable.3.5 Data. Not applicable.3.6 Safety. Thi
17、s standard may involve hazardous materials, operations, and equipment. This standard doesnot propose to address all the safety problems associated with its use. It is the responsibility of the user of thisstandard to establish appropriate safety and health practices and determine the applicability o
18、f regulatorylimitations prior to use.3.7 Documentation. Samples of components or material released to this standard shall be tested forconformity with the requirements of this standard and approved by the responsible GM Department prior to thestart of delivery of production level components or mater
19、ials.Any change to the component or material, e.g., design, function, properties, manufacturing process and/orlocation of manufacture requires a new release of the product. It is the sole responsibility of the supplier toprovide the customer, unsolicited, with documentation of any change or modifica
20、tion to the product/process,and to apply for a new release.If not otherwise agreed to, the entire verification test shall be repeated and documented by the supplier prior tostart of delivery of the modified or changed product. In some cases, a shorter test can be agreed to betweenthe responsible GM
21、department and the supplier.3.7.1 Test Results. With reference to this standard the results shall be represented in a test report.Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,
22、-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14670 Copyright 2012 General Motors Company All Rights ReservedNovember 2012 Page 3 of 54 Requirements and Procedure4.1.1 Pre-treatment. In order to meet the requirements of this standard it is necessary that road wheels shallundergo suitable cleaning followe
23、d by appropriate pre-treatment (e. g. multi-cation-phosphating with sufficientcoating weight; Iron phosphate is not allowed) before organic coat application.4.1.2 Composition and Surface Condition. Wheels shall show no surface characteristics which impaircorrosion resistance, e.g. burrs and/or weldi
24、ng deposits. Single coat systems of steel wheels (seeparagraph 1.2.1) shall only be used in addition with wheel covers. Multi-coat systems shall be triple-layer atleast. Clear coat shall be used for top coating. Double-layer types are only permissible for inflatable spare tires.4.2 Organic Coat Requ
25、irements.4.2.1 The coated steel wheel shall be smooth and free from any surface blemishes prejudicial to serviceability,appearance, or subsequent processing.4.2.2 Coating Thickness. The coating thickness shall be determined using an apparatus based on eddycurrent or ferromagnetic principles to withi
26、n 2 m (see Table 1).Table 1: Coating ThicknessType A Type B Type C Type DDisk inner t18 m (18 to 30) m t18 m t18 mTread t18 m t18 m t18 m t18 mDisk outer t18 m (18 to 30) m (40 to 80) m t60 mVisible areas rim flange t18 m (18 to 30) m (40 to 80) m t60 m4.3 Tests.4.3.1 Scratch Resistance. According t
27、o GMW14698 Tip 2, 4 N minimum.Requirement: No visible penetration in the as received condition only.4.3.2 Cross Hatch Test. According to GMW14829 Method A - Rating 0 or 1, in delivery conditions, after saltspray fog testing (paragraph Salt Spray Fog Testing) and after delamination test (paragraph Re
28、sistance to hotwater immersion).4.3.3 Salt Spray Fog Testing. 336 h according to GMW3286.No corrosion, except along the scribe line, blisters or any change of surface are allowed. Total corrosioncreepback according to GMW15282 shall be 3 mm maximum. Slight rust is permitted but shall not exceed 5 %o
29、f the length of the exposed edges.4.3.4 Scab-test. Scab test according to GMW15288 (4 weeks). Corrosion creepback according to GMW15282shall be 6 mm in total.4.3.5 Cyclic Corrosion Test (only applicable for Type D). After exposure to cyclic corrosion testingaccording to GMW14872, EXT, All, 4 s, Meth
30、od 1/2, Exposure C the parts shall meet the cosmeticperformance requirements of GMW15272. Part performance records shall be kept for reference and beavailable for review.4.3.6 Resistance to Stone Impact. Resistance to stone impact according to GMW14700.4.3.6.1 Type A, B and C. Not required4.3.6.2 Ty
31、pe D.Method A or B: Rating 8Method C: Rating 84.3.7 Resistance to Cleaning Agents. According to GMW14334-B-Rating 2.4.3.8 Resistance to Fuel. According to GMW14333 Method A - Rating 2.4.3.9 Resistance to Color Change. Fuel oil soot test according to GMW14701.4.3.9.1 Type A, B and C. Not requiredCopy
32、right 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 GMW14670 Copyright 2012 General Motors Company All Rights ReservedNovember 2012 Page 4 of 54.3.9
33、.2 Type D. Rating 84.3.10 Resistance to Hot Water Immersion. Delamination test according to GMW14704.Test paint adhesion according to GMW14829 Method A. Test specimen should fulfill cross hatch testaccording with a Rating 0 or 1.4.3.11 Weather Resistance. The test shall be performed optionally in fo
34、llowing test equipments according toparagraph 4.3.11.1, 4.3.11.2 or 4.3.11.3.This test is not applicable for Type A and C.Requirements (unless otherwise specified by personnel engineering):The surface finish shall show no significant deterioration such as change in surface appearance (e.g. cracking,
35、blistering or other surface destruction or loss of adhesion), change in gloss, colour change or other defectsdetrimental to serviceability, which cannot be removed by polishing.4.3.11.1 Method Accelerate Weathering. According to SAE J2527-A Extended UV Filters, 2500 kJ/m2exposure to exterior Xenon a
36、rc Weatherometer.4.3.11.2 Method Outdoor Weathering. According to GMW14873 for two years.Note: If a supplier shall be able to prove a positive result of two years outdoor exposure the acceleratedweathering test is not necessary.Accepted outdoor exposure locations are listed below:GME and GMNA: Expos
37、ure in Florida, 5 from horizontal, facing south, black box, without heating (accordingto GMW14873).GM Holden: Exposure in Allunga, Queensland, Australia. 180 K Langleys, exposed due north 5 fromhorizontal (southern hemisphere).LAAM: Cruz Alta Proving Ground Exposure, 5 from horizontal, facing north,
38、 black box, without heating,180 000 Langleys (according to SAE J1960).4.4 Additional Requirements. Other additional requirements may be specified on the relevant engineeringdrawings, material specifications, etc.5 Provisions for ShippingNot applicable.6 Notes6.1 Glossary. Not applicable.6.2 Acronyms
39、, Abbreviations, and Symbols. Not applicable.7 Additional Paragraphs7.1 All parts or systems supplied to this standard must comply with the requirements of GMW3059, Restrictedand Reportable Substances for Parts.8 Coding SystemThis standard shall be referenced in other documents, drawings, etc., as f
40、ollows:“Painted, Performance to GMW14670 - Type XXX”Where:GMW14670 = StandardType XXX = Type to paragraph 1.3Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGIN
41、EERING STANDARDS GMW14670 Copyright 2012 General Motors Company All Rights ReservedNovember 2012 Page 5 of 59 Release and RevisionsThis standard was originated in October 2005. It was first approved by Global Materials Team May 2006. Itwas first published in May 2007.Issue Publication Date Description (Organization)1 MAY 2007 Initial publication.2 NOV 2012 5 year refresh update (Finishes & Coatings GSSLT)Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
