1、 WORLDWIDE ENGINEERING STANDARDS Material Specification GMW16284 Brake Rotor Coating Copyright 2012 General Motors Company All Rights Reserved May 2012 Originating Department: GME Specification Center Page 1 of 9 1 Scope This specification defines the paint performance requirements for brake rotors.
2、 1.1 Material Description. The material of this specification is intended for spray or dip/spin painting applications. 1.2 Symbols. Not applicable. 1.3 Typical Applications. Brake rotors. 1.4 Remarks. The brake rotor coating is identified by the specification number, GMW16284, coating location on th
3、e rotor and pre-conditioning temperature. Type A coating location requires paint on the outside wall of the hat and edge of the brake rotor. Type B coating location includes the locations required in Type A and the wheel mounting surface. Type C coating location requires the locations in Types A and
4、 B along with the braking surfaces. Pre-conditioning requires one of the four time/temperature schedules identified as: No pre-conditioning, +200 C, +300 C, and +400 C. 2 References Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specificati
5、ons. ASTM D3363 ISO 2808 ISO 15184 2.2 GM Standards/Specifications. GMW3059 GMW14700 GMW14872 GMW15357 GMW3286 GMW14729 GMW14925 GMW14448 GMW14829 GMW15282 2.3 Additional References. TMC003 Material Safety Data Sheet guidance documents (available at ). 3 Requirements 3.1 Requirements on Test Specime
6、ns. Rotor shall be positioned vertically to represent vehicle position during corrosion testing, with the balance cut, if applicable, positioned at the 12 oclock position. Post-test evaluation shall be conducted on the required painted surfaces from 9 oclock to 3 oclock position on the test rotor. 3
7、.2 General. 3.2.1 Coatings shall be free of Chrome VI. 3.2.2 Chrome VI used as an adhesion promoter is not allowed. 3.2.3 Post-treatment, if performed, shall be Chrome VI free. 3.2.4 Rotors shall be free of processing fluids, rust preventatives and machining debris prior to coating. Copyright Genera
8、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 GMW16284 Copyright 2012 General Motors Company All Rights Reserved May 2012 Page 2 of 9 3.3 Coating Thicknes
9、s and Appearance. 3.3.1 The applicator will utilize approved paints as identified in the approved source list. Each approved paint material will be identified according to required thickness and tolerance. Approved source lists will be maintained according to paragraph 6 of this standard. 3.3.2 Coat
10、ing thickness shall be measured per ISO 2808. The average thickness shall be determined by a minimum of four evenly spaced readings around the circumference on all specified coated surfaces. Coating thickness to be evaluated on machined surfaces, as-cast surfaces are excluded. Coated areas that cann
11、ot be measured directly can be measured on an adjacent surface. The coating thickness shall be documented per Appendix A, Table A1. 3.3.3 Coating Defects. Drips and runs are permissible if they are 1 cm2 and 10 cm2 total surface area on either braking surface. Drips on the wheel mounting surface are
12、 not permissible if they affect the torque tension requirements of the wheel mount attachment. The wheel bearing mount surface and wheel bearing hub/pilot shall be free of paint. 3.3.4 The coating locations on the rotor shall be specified as Type A, B, or C. The application locations and thickness r
13、equirements are shown in Figures 1 through 3. If no coating type is specified, Type C shall apply. 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 STA
14、NDARDS GMW16284 Copyright 2012 General Motors Company All Rights Reserved May 2012 Page 3 of 9 Figure 1: Type A Coating Application Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS
15、-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16284 Copyright 2012 General Motors Company All Rights Reserved May 2012 Page 4 of 9 Figure 2: Type B Coating Application Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking p
16、ermitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16284 Copyright 2012 General Motors Company All Rights Reserved May 2012 Page 5 of 9 Figure 3: Type C Coating Application 3.3.5 The coating shall be black, gray, or silver in appearance. The coating approval will identify th
17、e color. Damage to coating is permissible provided it meets the corrosion testing requirements defined in paragraph 3.5. 3.4 Crosshatch Test. Paint adhesion shall be tested according to GMW14829, Rating 0 or 1 at delivery conditions, finished rotor completely cured and after high humidity exposure a
18、ccording to paragraph 3.6. 3.5 Corrosion Testing. Corrosion testing shall be performed on production intent parts. Corrosion requirements apply only to the required painted surfaces as defined in paragraph 3.3.4. Any additional exceptions shall be further defined on the part drawing. Corrosion testi
19、ng shall be performed on cured, pre-conditioned rotors as described in paragraph 3.5.1 and on rotors processed using the intended cure temperature without pre conditioning. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or netw
20、orking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16284 Copyright 2012 General Motors Company All Rights Reserved May 2012 Page 6 of 9 3.5.1 Pre-conditioning. The rotors shall be pre-conditioned at the following part temperatures and times prior to corrosion testing
21、 described in paragraphs 3.5.2, 3.5.3, 3.6, and 3.7. If specific pre-conditioning is not specified on the drawing or purchase order then paragraph 3.5.1.1 shall apply. Parts shall be naturally cooled to room temperature prior to performance testing. 3.5.1.1 No Pre-conditioning. The parts are not pre
22、-conditioned at elevated temperature. The parts are tested after normal application and curing. 3.5.1.2 For +200 C. (+200 20) C for (60 5) minutes object temperature. 3.5.1.3 For +300 C. (+300 20) C for (60 5) minutes object temperature. 3.5.1.4 For +400 C. (+400 20) C for (60 5) minutes object temp
23、erature. 3.5.2 Cyclic Corrosion Test. After exposure to cyclic corrosion testing per GMW14872, EXT, All, 4s, Method 1/2, the parts shall have a corrosion Rating of 9 or better per GMW15357 after 6 test cycles, and a Rating of 7 or better after Exposure C. The corrosion ratings apply only to the requ
24、ired coating application locations defined in paragraph 3.3.4. Part performance records shall be kept for reference and be available for review. 3.5.3 Salt Spray Fog Test. Parts shall be exposed to salt spray fog per GMW3286 for 168 h. There shall be 10 % red rust. 3.5.3.1 Non-Zinc Based Coatings. F
25、or non-zinc based coating only, total corrosion creepback according to GMW15282 shall be 3 mm maximum (e.g., bare iron). The evaluation of the creepback can be realized by blowing with compressed air or by using adhesive tape. Slight rust is permitted but shall not exceed 20 % of the length of expos
26、ed edges. Red rust “bleed out” from non-coated areas on the part shall not be considered in the evaluation. 3.6 Resistance to High Humidity Environment. Painted parts shall be exposed for 96 h to a high humidity environment according to GMW14729 with no evidence of blistering or any other change of
27、appearance. 3.7 Stone Impact Resistance. Test to GMW14700, Method C. Chip size Rating shall be 7 minimum. Only chips to substrate will be rated. Chip frequency shall be a maximum of High. The test piece wherever possible shall be the finished part. If this is impracticable, the test shall be conduct
28、ed on samples cut from the finished part, or, if necessary, specially prepared coated test panels with equal substrate and painting material. 3.8 Hardness. The coating shall have a minimum hardness of 3H per ISO 15184 or ASTM D3363, 2 h after application for +400 C type coatings. 4 Manufacturing Pro
29、cess Not applicable. 5 Rules and Regulations 5.1 Legal Regulations. All materials must satisfy applicable laws, rules, regulations and recommendations valid in the country of usage. 5.2 Language. In the event of conflict between the English and domestic language, the English language shall take prec
30、edence. 5.3 Inspection and Rejection. Samples of components or materials released to a GM material specification shall be tested for conformity with the requirements of this material specification and approved by the responsible Engineering department prior to commencement of delivery of bulk suppli
31、es. A new approval must be received for any changes, e.g., properties, manufacturing process, location of manufacture, etc. If not otherwise agreed, all testing and documentation normally required for initial release must be completed. It is the responsibility of the supplier to inform the customer
32、in a timely manner, without solicitation, and to include 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 to commencement of delivery of non-conforming bu
33、lk supplies. In individual cases, a shorter test can be agreed to between the responsible Engineering department and the supplier. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-
34、,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16284 Copyright 2012 General Motors Company All Rights Reserved May 2012 Page 7 of 9 5.4 Initial Source Approval. No shipments shall be made by any supplier until representative initial production samples have been approved by the appropriate Materials Engin
35、eering department(s) as meeting the requirements of this specification. 5.5 Material Safety Data Sheets/Safety Data Sheets (MSDS/SDS). For new product submissions, or when a change in chemical composition of an existing product has occurred, a complete copy of the Material Safety Data Sheet/Safety D
36、ata Sheet must be submitted in compliance with the Globally Harmonized System of Classification and Labeling of Chemicals (GHS) requirements or other country-specific MSDS/SDS requirements. In addition, product MSDS/SDS submissions must be in compliance with specific country General Motors TMC003 Ma
37、terial Safety Data Sheet/Safety Data Sheet guidance documents where available. 5.6 All materials supplied to this standard must comply with the requirements of GMW3059, Restricted and Reportable Substances for Parts. 6 Approved Sources Engineering qualifications of an approved source are required fo
38、r this standard. Only sources listed in the GM Materials File (GM Supply Power) under this standard number have been qualified by Engineering as meeting the requirements of this standard. For other GM locations, the responsible Engineering group should be contacted to obtain the approved source in t
39、hat individual country. 7 Notes 7.1 Glossary. Not applicable. 7.2 Acronyms, Abbreviations, and Symbols. GHS Globally Harmonized System of Classification and Labeling of Chemicals MSDS Material Safety Data Sheet SDS Safety Data Sheet 8 Coding System This standard shall be referenced in other document
40、s, drawings, etc., as follows: Material per GMW16284 Type y, z Where: y = Coating Type according to paragraph 3.3.4 z = Pre-conditioning temperature according to paragraph 3.5.1 9 Release and Revisions This standard was originated in August 2009. It was first approved by the Finishes and Coatings GS
41、SLT in June 2010. It was first published in June 2010. Issue Publication Date Description (Organization) 1 JUN 2010 Initial publication. 2 JAN 2011 Revised 1.4, 3.3.2, Figures 1 thru 3 and section 3.5 (Finishes and Coatings GSSLT) 3 MAY 2012 Paragraph 3.5 revised, paragraph 3.8 added (Finishes and C
42、oatings GSSLT) 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 GMW16284 Copyright 2012 General Motors Company All Rights Reserved May 2012 P
43、age 8 of 9 Appendix A Table A1: Coating Thickness Documentation GM Part Number Supplier Part Number Coating/Manufacturer Coating Type (A, B or C) Measurement Location: Thickness (mm) Outboard Brake Plate A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 Inboard Brake Plate B1 B2 B3 B4 B5 B6 B7 B8 B9 B10 B11 B1
44、2 Outboard Gooseneck C1 C2 C3 C4 Inboard Gooseneck D1 D2 D3 D4 Hat E1 E2 E3 E4 Wheel Mounting Location F1 F2 F3 F4 F5 F6 F7 F8 Inboard Vent G1 G2 G3 G4 Outboard Vent H1 H2 H3 H4 Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or
45、 networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16284 Copyright 2012 General Motors Company All Rights Reserved May 2012 Page 9 of 9 Table A2: Required Qualification Tests for Approval of New Materials Specification/Paragraph Title/Comment 3.2.1, 3.2.2, 3.2.2
46、 Coating Free of Cr VI 3.3.2 Coating Thickness 3.3.3 Coating Defects 3.3.4 Coating Locations Comment: Specific coating locations to be selected based on capability of the coating to meet Friction surface cleanability and wheel attachment loosening requirements 3.4 Crosshatch Test 3.5.1 Pre-condition
47、ing and non preconditioned Comment: Pre-conditioning temperature to be selected according to coating capability. 3.5.2 Cyclic Corrosion Test 3.5.3 Salt Spray 3.6 Humidity 3.7 Stone Impact GMW14925 and Front/Rear Brake Corner Assembly Technical Specification Brake Corner Performance GMW14448 Wheel Attachment Loosening Test Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
