1、 ENGINEERING MATERIAL SPECIFICATION Date Action Revisions Rev 01 2018 05 25 Revised See Summary of Revisions G. Weber, NA 2011 06 28 Activated D. Drobnich, FNA Controlled document at www.MATS Copyright 2018, Ford Global Technologies, LLC. Page 1 of 8 FASTENER FINISH, ELECTROPLATED ZINC-NICKEL, WSS-M
2、21P51-A1 TRIVALENT CHROMIUM PASSIVATE, SILVER FASTENER FINISH, ELECTROPLATED ZINC-NICKEL, WSS-M21P51-A2 TRIVALENT CHROMIUM PASSIVATE, LUBRICATED SEALER, SILVER FASTENER FINISH, ELECTROPLATED ZINC-NICKEL, WSS-M21P51-A3 TRIVALENT CHROMIUM PASSIVATE, LUBRICATED SEALER, ENHANCED LUBRICITY, SILVER FASTEN
3、ER FINISH, ELECTROPLATED ZINC-NICKEL, WSS-M21P51-A4 TRIVALENT CHROMIUM PASSIVATE, LUBRICATED SEALER, DURABLE LUBRICITY, SILVER FASTENER FINISH, ELECTROPLATED ZINC-NICKEL, WSS-M21P51-A5 TRIVALENT CHROMIUM PASSIVATE, LUBRICATED SEALER, BLACK FASTENER FINISH, ELECTROPLATED ZINC-NICKEL, WSS-M21P51-A6 TR
4、IVALENT CHROMIUM PASSIVATE, LUBRICATED SEALER, ENHANCED LUBRICITY, BLACK 1. SCOPE The materials defined by these specifications are corrosion protective coatings over steel and iron substrates. All consist of an alkaline zinc nickel alloy and trivalent chromium passivate. A2, A3, A4, A5 and A6 are a
5、lso coated with a clear sealer to increase corrosion resistance and/or to provide consistent torque-tension control. 2. APPLICATION These specifications were released for materials used as corrosion protective coatings for fasteners and other standard parts used throughout the vehicle. Some of the p
6、rocesses used to produce these coatings may induce hydrogen embrittlement in parts with high hardness. Parts identified as being at risk for hydrogen embrittlement shall meet the requirements of WSS-M99A3-A. A1 Corrosion resistance for non-threaded standard parts A2 Corrosion resistance plus lubrica
7、tion for threaded fasteners such as self tapping screws, thread forming screws for plastic and those with ISO metric screw threads; can be used in grounding applications A3 Corrosion resistance plus enhanced lubrication for threaded fasteners such as thread forming screws for metal; can be used in g
8、rounding screw applications A4 Corrosion resistance plus a special lubricant specifically designed for conical wheel nuts A5 Class A black appearance with corrosion resistance plus lubrication for threaded fasteners such as self tapping screws, thread forming screws for plastic and those with ISO me
9、tric screw threads A6 Class A black appearance with corrosion resistance plus enhanced lubrication for fasteners such as thread forming screws for metal ENGINEERING MATERIAL SPECIFICATION WSS-M21P51-A1/A2/A3/A4/A5/A6 Copyright 2018, Ford Global Technologies, LLC. Page 2 of 8 2.1 SERVICE APPLICATION
10、2.1.1 The recommended maximum continuous service temperature is 310C. 2.1.2 A2 and A3 exhibit electrical continuity to the substrate and are suitable for most electrical grounding applications. 3. REQUIREMENTS 3.1 APPROVED SOURCES This specification requires the use of approved sources. Only the sou
11、rces identified on the Ford Approved Source List (ASL) can be used when this specification is listed on the drawing, CAD file, or other documents. The list of approved sources is located within Ford at or available externally through a Ford Materials Engineer. 3.2 EMBRITTLEMENT Parts coated to this
12、 specification shall be free from the detrimental effects of hydrogen embrittlement or other factors which result in part brittleness. All parts shall meet the requirements of WSS-M99A3-A. 3.3 COATING APPLICATION 3.3.1 Applicators shall follow material supplier procedures and recommendations for che
13、mical usage, equipment, analysis, and processing. Applicators must have documentation to show that procedures and recommendations are being followed. 3.3.2 Prior to coating, the substrate shall be free of oil, dirt, and similar foreign materials. If a cleaning process is necessary, it shall have no
14、detrimental effect on the substrate, including freedom from embrittlement. See WSS-M99A3-A. 3.3.3 The sealers used under this specification do not require curing. The sealers shall be dried in place using hot air, typically in a spin dryer. Drying on a conveyer and other drying methods may be approp
15、riate. 3.3.4 The applicator shall follow the material suppliers recommendations concerning the drying temperature and spin speeds suitable for the basket diameter being used. 3.4 COATING APPEARANCE 3.4.1 The base zinc-nickel plating will have a metallic silver appearance prior to passivate applicati
16、on. 3.4.2 The passivate layer for A1, A2, A3 and A4 will have an appearance of slight iridescence and color variation consistent with interference films (e.g. yellow, orange, green, blue, purple variegation). 3.4.3 The passivate layer for A5 and A6 will be black. 3.4.4 The sealers used for A2, A3, A
17、5 and A6 will be a translucent film free from discontinuities. ENGINEERING MATERIAL SPECIFICATION WSS-M21P51-A1/A2/A3/A4/A5/A6 Copyright 2018, Ford Global Technologies, LLC. Page 3 of 8 3.4.5 The sealer used for A4 will be a translucent film but may contain some discontinuities in the form of touch
18、marks or blemishes; however, they shall not adversely affect the mechanical performance or corrosion resistance of the part. 3.4.6 The sealers used for A2 and A3 may have additional color ID of green or blue. 3.5 COATING PROPERTIES 3.5.1 Composition The alkaline base zinc-nickel plating shall have a
19、 nickel content of 12 to 17% as measured by calibrated X-ray fluorescence spectrometers in accordance with the suppliers requirements. The plating shall be a uniform, homogeneous alloy of zinc and nickel throughout the thickness of the deposit and across the high and low current densities of the par
20、t. Zinc-nickel alloy is the only deposit to be applied directly to the base. The use of a zinc strike is not permitted. The composition of the zinc-nickel plating, passivate, and water soluble lubricated sealer shall all be in accordance with the chemical suppliers requirements. 3.5.2 Thickness (AST
21、M B659 / ASTM B487) 3.5.2.1 The electroplated zinc-nickel layer shall have a thickness of 8 to 14 micrometers measured on flat surfaces. In case of dispute, the thickness measurement umpire method shall be metallographic sectioning per ASTM B487. 3.5.2.2 The passivate layer thickness is not subject
22、to measurement but will be less than 500 nanometers and greater than 50 nanometers. 3.5.2.3 The sealer layer thickness is not subject to measurement but will be less than 2 micrometers and greater than 0.5 micrometers. The thickness shall be sufficient to meet the corrosion requirements of the subst
23、rate material as well as the friction requirements. 3.5.2.4 The typical overall thickness of these coatings is 10 to 12 micrometers. 3.5.3 Adhesion (ASTM B 571) The coating shall withstand normal handling, storage, and installation without flaking or peeling or other loss of adhesion. In addition, t
24、here shall be no blistering or flaking after baking for hydrogen de-embrittlement. Adhesion of the electroplate to the base metal must conform to the requirements of one of the following test methods per ASTM B 571 unless otherwise indicated. ENGINEERING MATERIAL SPECIFICATION WSS-M21P51-A1/A2/A3/A4
25、/A5/A6 Copyright 2018, Ford Global Technologies, LLC. Page 4 of 8 3.5.3.1 Heat Quench Test There shall be no blistering or chipping of the finish after heating coated parts to 220 +/- 5C for 30 +/- 5 minutes and quenching in water at room temperature. 3.5.3.2 Burnishing Test No blistering, lifting,
26、or peeling of the electroplate from the substrate is permitted following the burnishing test. 3.5.4 Torque Tension Performance (WZ101, Test Program B, M10x1.5 PC 8.8 surrogate bolt, 25.3 kN tension) When tested in accordance with Ford Worldwide Fastener Standard WZ101, coated fasteners shall have a
27、friction coefficient within +/- 0.03 of the nominal value below: WSS-M21P51-A2 0.14 WSS-M21P51-A3 0.11 WSS-M21P51-A4 0.16 WSS-M21P51-A5 0.14 WSS-M21P51-A6 0.11 3.6 RESISTANCE PROPERTIES 3.6.1 Laboratory Accelerated Cyclic Corrosion Test (CETP 00.00-L-467) A1: Non-Ferrous Corrosion 6 weeks Ferrous Co
28、rrosion 9 weeks A2, A3, A4, A5, A6: Non-Ferrous Corrosion 9 weeks Ferrous Corrosion 12 weeks Evidence of corrosion products in excess of ASTM D 610, grade 6 (1%) on significant surfaces following at the specified test interval constitutes a failure. Evaluation shall be done without magnification at
29、a normal reading distance. 3.6.2 Water Resistance 240 hours (FLTM Bl 104-01) The finish shall not blister or show any signs of ferrous corrosion. Adhesion shall meet the requirements in section 3.5.3. 3.6.3 Fluid Resistance (FLTM BI 168-01, Method A, Gasoline, Diesel, Coolant, Engine Oil, Transmissi
30、on Fluid and Brake Fluid, other fluids as appropriate for application) The finish shall not blister or show any signs of softening or dulling. Adhesion shall meet the requirements in section 3.5.3. ENGINEERING MATERIAL SPECIFICATION WSS-M21P51-A1/A2/A3/A4/A5/A6 Copyright 2018, Ford Global Technologi
31、es, LLC. Page 5 of 8 3.6.4 Accelerated Weathering (A5 such as, ISO 8401-1986 (E) - cylindrical mandrel bending ensuring bendability, must be used and results recorded 3.9 PROCESS CONTROL ITEMS Control items must be run as specified in Table 1 and control of these items must be represented in the PFM
32、EA and control plan. After review and sign-off of the control documents (PFMEA, CP and SPC data) for a significant number of lots, the frequency of the testing can be reduced as agreed upon by the Fastener Engineering representative. Other testing in this specification is for initial approval or on
33、an “as requested” basis and is not required for annual recertification. 3.9.1 Neutral Salt Spray Corrosion Test (SAE/USCAR-1, ASTM B 117) A1: Non-Ferrous Corrosion 120 hours Ferrous Corrosion 600 hours A2, A3, A4, A5, and A6: Non-Ferrous Corrosion 240 hours Ferrous Corrosion 960 hours Neutral salt s
34、pray (NSS) testing shall not be used in demonstrating initial conformance to this specification. Fasteners coated to these specifications shall be tested and evaluated in accordance with SAE/USCAR-1, both in the as-plated, trivalent chromium and sealed condition (as-processed) and after being held a
35、t 120 C for 4 hours (baked), and shall have the specified NSS performance. ENGINEERING MATERIAL SPECIFICATION WSS-M21P51-A1/A2/A3/A4/A5/A6 Copyright 2018, Ford Global Technologies, LLC. Page 6 of 8 4. GENERAL INFORMATION The information given below is provided for clarification and assistance in mee
36、ting the requirements of these specifications. Contact for questions concerning Engineering Material Specifications. 4.1 SIGNIFICANT SURFACES Significant surfaces should be noted on the Engineering Drawing. If not noted there, significant surfaces are generically defined as those surfaces of the fi
37、nished part that: Are directly visible when the finished part is assembled in position. Can be a source of corrosion products directly visible, visible by reflection, or visible when they run down the part or onto other parts. Can affect fit or function of the part. Note: Small areas of ferrous corr
38、osion may be allowed on sharp edges, corners, and recesses due to reduced coverage of the electroplating. Recesses are generally defined as areas unreachable by a 13 mm (0.5 inch) diameter sphere. 4.2 WORLDWIDE FASTENER FINISHES When used for Worldwide Standard Parts, the Worldwide Fastener Finish S
39、uffix as defined in Worldwide Fastener Standard WX100 shall be specified as shown below: WSS-M21P51-A2 S450 WSS-M21P51-A3 S450L WSS-M21P51-A5 S450B WSS-M21P51-A6 S450BL 4.3 RECOMMENDED TESTING REQUIREMENTS FOR DESIGN VALIDATION, PRODUCTION VALIDATION, AND SREA. Coating performance is a function of m
40、aterial selection, surface preparation, and coating application. For established coatings and coating lines, this may permit a reduced test schedule to validate compliance to this specification. Use Table 1 below to determine the recommend test plan depending on the situation. This specification can
41、not prove out parts or coatings that involve changes in vehicle environment such as increased stone chipping or increased temperature. These changes may require vehicle testing, consult SDS/ARL requirements. 4.4 APPROVAL OF MATERIALS Suppliers desiring approval of their materials shall first obtain
42、an expression of interest from Purchasing, Design or Product Development, and Materials Engineering. The supplier shall submit a completed copy of their laboratory test reports, signed by a qualified and authorized representative of the test facility, demonstrating full compliance with all the requi
43、rements of the Material Specification. Tested material samples must be available for review upon request and kept for a minimum of one year. Upon request, the supplier will review the associated quality control documents (Process Failure Mode and Effects Analysis, Control Plans, Certification testin
44、g) with Ford. 4.5 SUPPLIERS ONGOING RESPONSIBILITY ENGINEERING MATERIAL SPECIFICATION WSS-M21P51-A1/A2/A3/A4/A5/A6 Copyright 2018, Ford Global Technologies, LLC. Page 7 of 8 All materials must be equivalent in all characteristics to the material upon which approval was originally granted. Prior to m
45、aking any changes to the material originally approved, whether or not such changes affect the materials ability to meet the specification requirements, the supplier shall notify the affected Supplier Technical Assistance (STA), Purchasing, and Materials Engineering activities of the proposed changes
46、 (with reasons) by submission of a completed Suppliers Request for Engineering Approval, SREA. For parts and components using Ford Engineering Material Specifications, all samples tested to the specifications for Design Verification (DV), Production Verification (PV) and Production Part Approval Pro
47、cess (PPAP) sign off must be kept until Job 1. 4.3 RESTRICTED SUBSTANCE MANAGEMENT STANDARD Substance restrictions imposed by regulations or Company direction applies to the materials addressed by this document. The restrictions are identified in the Restricted Substance Management Standard WSS-M99P
48、9999-A1 which is updated yearly. It is the suppliers responsibility to comply with this standard on a continuing basis through IMDS and or GMAP reporting. ENGINEERING MATERIAL SPECIFICATION WSS-M21P51-A1/A2/A3/A4/A5/A6 Copyright 2018, Ford Global Technologies, LLC. Page 8 of 8 TABLE 1 New Coating Ma
49、terial Established Coating Material All Applicators New Applicator Existing Applicator Test Requirement All Parts Existing Part New Part Initial PPAP Production Control Process Change Example A Example B Example C Example D Example E 3.5.1 Composition X X X 1/lot 3.5.2 Thickness X X X 1/lot 3.5.3 Adhesion X X X 3.5.4 Torque Tension Performance X X X1 1/daily1 3.6.1 Laboratory Accelerated Cyclic Corrosion X X Contact Fastener or Materials Engineering 3.6.2
