1、 ENGINEERING MATERIAL SPECIFICATIONDate Action Revisions 2011 02 25 No replacement named. No longer in use. G. Weber, NA N-STATUS 2005 10 27 Revised Para 2 and 3.4.1, 3.7.2, 3.9 and 3.12 A. Cockman 2004 09 20 Activated T. Hermansson Printed copies are uncontrolled Copyright 2011, Ford Global Technol
2、ogies, LLC Page 1 of 4 CORROSION PROTECTIVE COATING, ELECTRO PLATED ZINC WSS-M21P46-A1 IRON ALLOY, TRIVALENT PASSIVATE WITH WATERBORNE TOP COAT, BLACK NOT TO BE USED FOR NEW DESIGN 1. SCOPE The materials defined by this specification are corrosion protective coatings applied sequentially per supplie
3、r specifications over steel. They consist of an alkaline zinc iron alloy electrodeposit and a trivalent chromium passivate/tie coat followed by an waterborne inorganic top coat. When used with an integrated torque modified, the processes provide consistent torque-tension control. All processes are f
4、ree of hexavalent chromium, lead and cadmium. 2. APPLICATION This specification was released for materials used as corrosion protective coatings over steel fasteners and small parts. The processes may induce hydrogen embrittlement and therefore these coatings must be hydrogen embrittlement relieved
5、when applied to high hardness parts in accordance with WSS-M99A3-A. The cure temperature of the inorganic top coat is 80 150 C. These coatings shall not be specified if this temperature adversely affects the component being coated. 2.1 SERVICE TEMPERATURE The maximum continuous service temperature i
6、s 200 C. 3. REQUIREMENTS 3.1 STANDARD REQUIREMENTS FOR PRODUCTION MATERIALS Material suppliers and part producers must conform to the Companys Quality System Requirements for Production Materials (WSS-M99P1111-A). Part producers must use approved materials specified on the Companys Approved Source L
7、ist. 3.2 APPROVED APPLICATOR QUALITY REQUIREMENTS Applicators must follow coating manufacturer procedures and recommendations for chemical usage, equipment, analysis and processing. 3.3 APPEARANCE 3.3.1 The ZnFe coating will have a metallic silver appearance prior to passivate/tie coat application.
8、ENGINEERING MATERIAL SPECIFICATIONWSS-M21P46-A1 Copyright 2011, Ford Global Technologies, LLC Page 2 of 4 Printed copies are uncontrolled 3.3.2 The passivate/tie coat will have a black appearance 3.3.3 The transparent inorganic top coat used will be a wax containing polysilicate based film free from
9、 discontinuities. 3.4 COATING COMPOSITION 3.4.1 The alkaline ZnFe electrodeposit shall have a iron content of 0.3 to 0.8wt% as measured by calibrated X-ray fluorescence spectrometers in accordance with the suppliers requirements. 3.4.2 The passivate/tie coat shall have a composition in accordance wi
10、th the chemical suppliers requirements. 3.4.3 The inorganic top coat shall have a composition in accordance with the chemical suppliers requirements. 3.5 COATING THICKNESS 3.5.1 The ZnFe electrodeposit will have an optimum thickness of 8 +/- 2 microns measured on flat surfaces. 3.5.2 The passivate/t
11、ie coat thickness is not subject to measurement but will be less than one micron. 3.5.3 The inorganic top coat thickness is typically between 0.5 and 3 microns. The minimum thickness shall be sufficient to meet the corrosion requirements of the substrate material. 3.5.4 Excessive coating thickness o
12、n threaded components may cause assembly concerns. The general requirements of the Ford Worldwide Fastener Standards, Finish Specification WX100, and Section 5 apply to these coatings. 3.6 THREAD ACCEPTANCE REQUIREMENTS (WA900, WE900, WX100) For thread acceptance requirements see Ford Worldwide Fast
13、ener Standards WA900, WE900 and WX100. 3.7 CURING AND TRANSPORTATION 3.7.1 The ZnFe electrodeposit with passivate/tie coat will be cured and packaged in accordance with suppliers requirements prior to transportation to a subsequent coating applicator. 3.7.2 The organic top coat shall be cured for 15
14、 min at a temperature of 80 150 C. 3.7.3 These coatings shall not be used on materials that are adversely affected by these metal temperatures. ENGINEERING MATERIAL SPECIFICATIONWSS-M21P46-A1 Copyright 2011, Ford Global Technologies, LLC Page 3 of 4 Printed copies are uncontrolled 3.8 CLEANING Prior
15、 to coating, the substrate shall be free of oil, dirt, and similar foreign materials. If a cleaning process is necessary, it shall have no detrimental effect on the substrate, including freedom from embrittlement. 3.9 ADHESION The coating shall withstand normal handling, storage, and installation wi
16、thout flaking or peeling or other loss of adhesion. The coating must also be possible to paint upon (with good adhesion of the subsequent paint) and to show a good adhesion with prevailing torque features. 3.10 TORQUE TENSION (WZ101) Applicators preparing the final layer of parts in accordance must
17、have torque tension measurement equipment in accordance with WZ 101. The coatings shall meet the torque and friction coefficient specified in Table 1. 3.11 RESISTANCE PROPERTIES 3.11.1 Corrosion resistance (SAE/USCAR-1, ASTM B 117, ASTM D 610, WX100) Fasteners shall be tested and evaluated in accord
18、ance with SAE/USCAR-1, and shall pass the number of hours specified in Table 1 and the “General Requirements” of WX100. Parts other than fasteners shall be tested in accordance with ASTM B 117. Parts shall show no single ferrous corrosion spot larger than 1.5 mm in diameter, and shall not exhibit fe
19、rrous corrosion overall exceeding 0.1%, per ASTM D 610, grade 8, after the number of test hours specified in Table 1. 3.11.2 Water Resistance (FLTM Bl 104-01) Shall not blister or show any signs of red rust when subjected to immersion in water for 240 hours. 3.11.3 Gasoline Resistance Shall not blis
20、ter or show any signs of softening or dulling when subjected to immersion in current factory fill gasoline for 24 hours at 23 +/- 2 C. 3.11.4 Hot Oil Resistance Shall not blister or show any signs of softening or dulling when subjected to immersion in engine oil (SAE 10W30 per WSE-M2C903-A2 or equiv
21、alent) for 24 hours at 66 +/- 3 C. ENGINEERING MATERIAL SPECIFICATIONWSS-M21P46-A1 Copyright 2011, Ford Global Technologies, LLC Page 4 of 4 Printed copies are uncontrolled 3.11.5 Ethylene Glycol Resistance Shall not blister or show any signs of softening or dulling when subjected to immersion in a
22、50% solution of water and long life coolant concentrate (WSE-M97B44-B or equivalent) for 24 hours at 23 +/-2 C. 3.11.6 Brake Fluid Resistance Shall not blister or show any signs of softening or dulling when subjected to immersion in currently approved brake fluid for 24 hours at 23 +/-2 C. 3.11.7 Po
23、wer Steering/Transmission Fluid Shall not blister or show any signs of softening or dulling when subjected to immersion in current factory fill power steering and transmission fluid for 24 hours at 66 +/-3 C. 3.12 ELECTRICAL CONDUCTIVITY This coating systems is not recommended for electrical groundi
24、ng applications. TABLE 1 GUIDANCE TO PROPERTIES OF WSS-M21P46-A1 COATING SYSTEM Specification Color Typ. Thickness m WZ 101 Torque NM (a) WZ 101 Friction Coefficient N.S.S. Hrs. Cosmetic corrosion/Ferrous Corrosion Min weeks VCC VICT or VDA test to Zinc Oxidation Min. weeks VCC VICT or VDA test to R
25、ed Rust Examples of Part Applications WSS-M21P46-A1 black 7 to 12 Mean: 44-49 3 Sigma: 38-55 Mean: .14 +/- .01 3 Sigma: .14 +/- .03 200 hours/ 500 hours 3 6 Fasteners with friction requirements and in moderate corrosion environment. Also for non threaded parts. (a) Based on WZ101 test program B for M10x1.5 PC 8.8 surrogate bolt. Torque values taken 25.3 kN tension
