1、 WORLDWIDE ENGINEERING STANDARDS Material Specification GMW16882 Appearance Standard for Decorative Chrome-plated Metals and Plastics Copyright 2013 General Motors Company All Rights Reserved February 2013 Page 1 of 9 1 Scope Note: Nothing in this standard supercedes applicable laws and regulations.
2、 Note: In the event of conflict between the English and domestic language, the English language shall take precedence. This standard describes the surface appearance and quality requirements for evaluating the appearance of production-level, chrome-plated, interior and exterior metal and plastic par
3、ts. Criteria is established for the determination of allowable appearance criteria based upon the significance of the chrome-plated surface as outlined in standard specifications for electrodeposited coatings for plastic and metal parts (ASTM B604 and ASTM B456, respectively). This specification def
4、ines appearance definitions for chrome-plated parts covered under GMW14668, GMW14672, GMW15613, and any other decorative chrome-plated performance specifications. ASTM B456 and ASTM B604 define significant surfaces as those surfaces normally visible (directly or by reflection) that are essential to
5、the appearance and/or serviceability of the article when assembled in normal position, or that can be the source of corrosion products that have the potential to deface visible and significant surfaces on the assembled article. If, after field exposure or accelerated corrosion testing, product corro
6、sion is experienced but not previously considered for degree of visibility, surfaces are permitted to be redefined on the drawing. Contact GM Materials Engineering or the part Subsystem Management Team (SMT) if assistance is needed in defining part surfaces. Table 1 defines minimum appearance criter
7、ia for surfaces based upon degree of visibility. These significant surfaces are to be defined by degree of visibility and indicated on the part drawings. Note: When defining these visible surfaces, the appearance of corrosion as a result of accelerated testing or field performance can affect the deg
8、ree of visibility of that surface and is also considered as part of the criteria defining the significance of that surface. 1.1 Material Description. Not applicable. 1.2 Symbols. Not applicable. 1.3 Typical Applications. Electroplated parts of the copper-nickel-chromium type as used on plastic or me
9、tal components where a bright or low-gloss decorative and/or protective finish is required. 1.4 Deviations. Deviations accepted by GM require, in every case, GM signed boundary samples that are stored by the supplier and accepted by both GM Design Appearance Quality and the respective assembly plant
10、. The visual comparison to accepted boundary samples is always the most decisive method. For evaluating appearances that are subject to interpretation, pick master and boundary samples that are acceptable to all parties involved through assembly. The supplier and GM assembly plant should agree on ta
11、rget and upper- and lower-limit boundary samples. Appearance Approval Report (AAR) samples should be used for standard reference and initial part submissions. The effects of potential corrosion need to be taken into account for any deviation consideration. Copyright General Motors Company Provided b
12、y IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16882 Copyright 2013 General Motors Company All Rights Reserved February 2013 Page 2 of 9 2 References Note: Only the latest approve
13、d standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. ASTM B456 ASTM B604 2.2 GM Standards/Specifications. GMW3059 GMW14668 GMW15613 GMW6992 GMW14672 2.3 Additional References. TMC003 Material Safety Data Sheet guidance documents (available at ). 3 Requirement
14、s 3.1 Requirements on Delivery. Exterior body parts are divided into different appearance zones to set the quality requirements of each zone separately (see Table 1). The zones are also specified on the drawing by the respective commodity authority. This is a macro perspective on appearance as it pe
15、rtains to significance of the surface. The GM Materials Engineer or SMT may also take into consideration the proximity of the part to the vehicle body position. Care must be taken in this case to account for any corrosion products that may affect the appearance after test or field performance. If th
16、e proximity of the part relative to on-vehicle position is to be taken into account, it must also be noted on the drawing. Any exclusions or deviations to this specification must be noted appropriately. Table 2 defines the quality criteria under which appearance can be based upon degree of visibilit
17、y of the significant surface. Appendix A provides examples of common surfaces and how they can be rated by degree of visibility in determining quality criteria for that surface. If necessary, contact the GM Materials Engineer. Table 1: Appearance Zones of a Part Zone Definition Description A Very Hi
18、gh Visibility A very highly visible surface is one that is fully exposed and fully visible. It is not recessed in any manner and stands proud of the vehicle, i.e., frontal grille surround, grille, lighting bezel frontal surfaces, bumper frontal surfaces and any chrome surface not angled or recessed
19、from the outer extremes of the vehicle and in full view. B High Visibility Surfaces may be highly visible; however, some degree of angled recess makes these surfaces less apparent than Zone A, i.e., upper or lower recesses of a grille surround with a highly visible back-protruding angle. C Moderate
20、Visibility Significant surfaces that may be somewhat hidden from the more visible surfaces (i.e., surfaces that are near 180 from front-facing surfaces), surfaces that are not clearly seen from a partial front view, and side walls of a part feature not seen from a frontal view. D Hidden After Instal
21、lation These surfaces are totally hidden from the customer, i.e., side flanges, back side of part, and chrome surfaces intentionally covered by other decorative parts. These surfaces are insignificant unless corrosion products can propagate to any visible surface. Refer to GMW6992 for lighting and o
22、ther required methods of evaluation. Deviations to this light source may be needed due to part design and environment, but this needs to be agreed upon with the affected GM personnel. For an outside evaluation, northern sky-oriented assessment direction at 11:00 A.M. is preferred. The evaluation sha
23、ll be performed at arms length (0.75 to 1) m and viewed in appropriate car position. 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 GMW1688
24、2 Copyright 2013 General Motors Company All Rights Reserved February 2013 Page 3 of 9 3.1.1 Additional Requirements. See Table 2 for quality requirements. Table 2: Quality Requirements for Appearance Attributes Appearance Attribute Description Zone A Zone B Zone C Zone D 1 Peeling (Plate Lifting) or
25、 Cracks Adhesion loss between substrate and plating. None allowed. None allowed. None allowed. Only allowed if it cannot be a source of corrosion product to any significant surface. 2 Blisters Adhesion loss between substrate and plating. None allowed. None allowed. None allowed. Only allowed if it c
26、annot be a source of corrosion product to any significant surface. 3 Pits, Dents Voids in the metal surface, other irregularities due to handling, sinks, shrinking or tooling imperfections upon gunsighting. 0.75 mm, maximum two (2) allowed per 400 mm. Uncounted under 0.25 mm and not felt by fingerna
27、il. 1.0 mm, maximum two (2) allowed per 50 mm. Uncounted under 0.25 mm and not felt by fingernail. 1.0 mm, maximum two (2) allowed per 50 mm. Uncounted under 0.25 mm. Allowed but must not be visible to the customer. 4 Skip Plate (Exposed Substrate, Lack of Plate) Area not covered by plate. None allo
28、wed. None allowed. None allowed. Only allowed if it cannot be a source of corrosion product to any significant surface. 5 Rough Surface Superficial abrasion or rough feel on the surface. Must not retain fibers from a cotton cloth when wiped, and not nor felt by fingernail or deface the attractivenes
29、s of the surface. Must not be considered widespread debris. Must not retain fibers from a cotton cloth when wiped, and not nor felt by fingernail or deface the attractiveness of the surface. Must not be considered widespread debris. Must not retain fibers from a cotton cloth when wiped, and not nor
30、felt by fingernail or deface the attractiveness of the surface. Must not be considered widespread debris. Allowed but must not retain fibers from a cotton cloth when wiped. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or netw
31、orking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16882 Copyright 2013 General Motors Company All Rights Reserved February 2013 Page 4 of 9 Appearance Attribute Description Zone A Zone B Zone C Zone D 6 Scratches Abrasion on the surface. Fine scratch not easily seen
32、 or felt by fingernail; not more than one (1) 20 mm or boundary scratch maximum per 200 mm. When strongly exposed, boundary samples are required. Boundary samples required. Boundary samples required. Allowed but must not be visible to the customer. 7 Chrome Stain Chromic acid stains (brown). None al
33、lowed. None allowed. None allowed. None allowed. 8 Blush Dull circular appearance at or near the gate area. None allowed. Boundary sample required. Boundary sample required. Allowed but must not be visible to the customer. 9 Sharp Edges Any edges that feel sharp or pull fibers from a cotton cloth. M
34、ust not retain fibers from a cotton cloth when wiped and must not be felt by fingernail. Must not retain fibers from a cotton cloth when wiped and must not be felt by fingernail. Must not retain fibers from a cotton cloth when wiped. Must not retain fibers from a cotton cloth when wiped or cause the
35、 opportunity for injury in handling. Boundary sample may be required. 10 Dirt, Stardust or Other Widespread Contaminants. Widespread Debris in Plate Resulting in Large Areas of Roughness. Pattern of dense particulate defects in any metal layer. None allowed. None allowed. None allowed. None allowed.
36、 11 Nickel Show Absence of chrome or other metal to specified requirement. None allowed. None allowed. None allowed. Only allowed if absolute confidence it will not migrate to any significant surface. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for R
37、esaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16882 Copyright 2013 General Motors Company All Rights Reserved February 2013 Page 5 of 9 4 Manufacturing Process Not applicable. 5 Rules and Regulations 5.1 Legal Regulations. All materia
38、ls 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 precedence. 5.3 Inspection and Rejection. Samples of components or materials releas
39、ed 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 supplies. A new approval must be received for any changes, e.g., properties, manufact
40、uring 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 in a timely manner, without solicitation, and to include documentation of all m
41、odifications 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 bulk supplies. In individual cases, a shorter test can be agreed to between the r
42、esponsible Engineering department and the supplier. 5.4 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 Data Sheet must be su
43、bmitted 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 Material Safety Data S
44、heet/Safety Data Sheet guidance documents where available. 5.5 All materials supplied to this standard must comply with the requirements of GMW3059, Restricted and Reportable Substances for Parts. 6 Approved Sources Materials supplied to this specification must be approved by General Motors. The app
45、ropriate GM Materials Engineering department(s) must confirm material as meeting the requirements of this specification. Any test data sheets of material submitted to General Motors for such confirmation (e.g., during Production Part Approval Process (PPAP) under this material specification must lis
46、t all properties and must apply corresponding test methods of this material specification. 7 Notes 7.1 Glossary. MATSPC: Global repository of GM approved materials for corresponding GM Engineering Standards. 7.2 Acronyms, Abbreviations, and Symbols. AAR Appearance Approval Report ASTM ASTM Internati
47、onal GHS Globally Harmonized System of Classification and Labeling of Chemicals GSSLT Global Subsystem Leadership Team MSDS Material Safety Data Sheet PPAP Production Part Approval Process SDS Safety Data Sheet SMT Subsystem Management Team Copyright General Motors Company Provided by IHS under lice
48、nse with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16882 Copyright 2013 General Motors Company All Rights Reserved February 2013 Page 6 of 9 8 Coding System This standard shall be referenced in other
49、 documents, drawings, etc., as follows: Material per GMW16882 9 Release and Revisions This standard was originated in November 2012. It was first approved by the Finishes & Coatings Global Subsystem Leadership Team (GSSLT) in February 2013. It was first published in February 2013. Issue Publication Date Description (Organization) 1 FEB 2013 Initial publication. Copyright General Motors Company Provided by IHS
