1、 ENGINEERING MATERIAL SPECIFICATION Material Name Specification Number Date Action Revisions 2002 06 11 Revised Completely revised, updated and renumbered D. Drobnich, A. Cockman 2001 08 08 Activated S. Renko, A. Cockman Printed copies are uncontrolled Page 1 of 5 Copyright 2002, Ford Global Technol
2、ogies, Inc. CORROSION PROTECTIVE COATING, ZINC-RICH INORGANIC WSS-M21P37-A1 BASECOAT, LUBRICATED ALUMINUM-RICH ORGANIC TOPCOAT, SILVER CORROSION PROTECTIVE COATING, ZINC-RICH INORGANIC WSS-M21P37-A2 BASECOAT, LUBRICATED ALUMINUM-RICH ORGANIC TOPCOAT, SILVER 1. SCOPE The materials defined by these sp
3、ecifications are corrosion protective coatings over steel. They consist of a zinc phosphate or an alkaline clean and mechanical (shot blast) pre-treatment, a zinc-rich basecoat, and an integrally lubricated aluminum-rich topcoat. This duplex coating system provides enhanced corrosion protection, col
4、or and/or consistent torque-tension control. They are free of chromium, nickel, lead and cadmium. 2. APPLICATION These specifications were released originally for materials used for corrosion protective coatings over steel. Since hydrogen embrittlement is not induced by the process, these coatings a
5、re suitable for high hardness parts. The cure temperature for the zinc-rich basecoat is 245 to 255 C and 200 to 220 C for the aluminum-rich topcoat. These coatings shall not be specified if this temperature adversely affects the component being coated. These coatings provide good bi-metallic corrosi
6、on resistance when in contact with aluminum. They should not be applied to parts in contact with uncoated copper, magnesium or stainless steel surfaces. 2.1 SERVICE TEMPERATURE The maximum continuous service temperature resistance of A1 and A2 is 260C. 3. REQUIREMENTS 3.1 STANDARD REQUIREMENTS FOR P
7、RODUCTION MATERIALS Material suppliers and part producers must conform to the Companys Standard Requirements For Production Materials (WSS-M99P1111-A). ENGINEERING MATERIAL SPECIFICATION WSS-M21P37-A1/A2 Page 2 of 5 Copyright 2002, Ford Global Technologies, Inc. 3.2 LICENSEE APPLICATOR QUALITY REQUI
8、REMENTS Applicators must follow coating manufacturer procedures and recommendations for chemical usage, equipment and processing. 3.3 MATERIAL PERFORMANCE 3.3.1 Raw Material Storage Stability The material must be capable of being stored at 23 +/- 2 C for 60 days without detrimental effect to the per
9、formance of the coated parts. 3.3.2 Cleaning Prior to coating, the parts shall be free of oil, scale, and similar foreign materials. The cleaning process shall have no detrimental effect on the substrate, including freedom from embrittlement. All parts must be zinc phosphated or degreased (alkaline
10、or vapor) and mechanically cleaned (shot blast). When shot blasting, S-70 (SAE J 444) type steel shot is recommended. When the zinc phosphate option is used, its coating weight shall be 6-10 g/m. 3.3.3 Curing The basecoat is typically cured at a metal temperature of 245 to 255 C and the topcoat at 2
11、00 to 220 C. The coating shall not be used on materials that are adversely affected by these metal temperatures. Parts must be sufficiently cured at the time of packing to withstand normal handling and shipping without marring. 3.3.4 Finished Condition Parts must be dry to touch such that, when held
12、 with a Watmans No.41 filter paper, or equivalent, and applying hand pressure for 5 to 10 seconds, there shall be no visible staining of the filter paper when viewed without using supplementary magnification. For referee purposes this test shall be carried out using a force of 10N. 3.3.5 Appearance
13、The coating shall be uniform in color and free from discontinuities when viewed without magnification. 3.3.6 Storage Life Parts supplied shall still meet the specific requirements of this specification 6 months after receipt by Ford when stored at 5 to 28 C with no direct heat or sunlight. ENGINEERI
14、NG MATERIAL SPECIFICATION WSS-M21P37-A1/A2 Page 3 of 5 Copyright 2002, Ford Global Technologies, Inc. 3.4 ADHESION The cured coating shall withstand normal handling, storage and installation without flaking or peeling or other loss of adhesion. Parts heated to 120 C for 60 minutes shall not exhibit
15、blistering, peeling, flaking or coating which can be removed by a filament type tape, such as 3M No. 898-2. The testing of coating quality by salt spray and/or determination of coating thickness will be done on parts passing the adhesion test. 3.5 RESISTANCE PROPERTIES 3.5.1 Corrosion Resistance (SA
16、E/USCAR-1, ASTM B 117, ASTM D 610, WX100) Fasteners shall be tested and evaluated in accordance 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
17、no single ferrous corrosion spot larger than 1.5 mm in diameter, and shall not exhibit ferrous corrosion overall exceeding 0.1%, per ASTM D 610, grade 8, after the number of test hours specified in Table 1. 3.5.2 Water Resistance (FLTM BI 104-01) Shall not blister or show any signs of red rust when
18、subjected to immersion in water for 240 hours. 3.5.3 Gasoline Resistance Shall not blister or show any signs of softening or dulling when subjected to immersion in current factory fill gasoline for 24 hours at 23 +/- 2 C. 3.5.4 Hot Oil Resistance Shall not blister or show any signs of softening or d
19、ulling when subjected to immersion in engine oil (SAE 10W30 per WSE-M2C903-A2 or equivalent) for 24 hours at 66 +/- 3 C. 3.5.5 Ethylene Glycol Resistance Shall not blister or show any signs of softening or dulling when subjected to immersion in a 50% solution of water and long life coolant concentra
20、te (WSE-M97B44-B or equivalent) for 24 hours at 23 +/- 2 C. ENGINEERING MATERIAL SPECIFICATION WSS-M21P37-A1/A2 Page 4 of 5 Copyright 2002, Ford Global Technologies, Inc. 3.5.6 Brake Fluid Resistance Shall not blister or show any signs of softening or dulling when subjected to immersion in currently
21、 approved brake fluid for 24 hours at 23 +/- 2 C. 3.5.7 Power 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. 3.6 COATING THICKNESS AND COATIN
22、G WEIGHT (MASS) (ASTM B 568/ISO 3497, ASTM B 499/ISO 2178) The coating thickness and minimum coating weight are given in Table 1. The coating thickness should be measured on flat surfaces using a magnetic induction thickness instrument (ASTM B 499/ISO 2178) or by calibrated X-ray fluorescence spectr
23、oscopy (ASTM B 568/ISO 3497), and should be based on an average of at least ten measurements. Alternatively, the thickness of the basecoat can be determined using a weigh-strip-weigh method. Details of this method are available from the coating manufacturer. 3.7 THREAD ACCEPTANCE REQUIREMENTS (WA900
24、, WE900, WX100) For thread acceptance requirements see Ford Worldwide Fastener Standards WA900, WE900 and WX100. 3.8 TORQUE-TENSION (WZ 101) The coating shall meet the required torque and friction coefficient specified in Table 1. ENGINEERING MATERIAL SPECIFICATION WSS- M21P37-A1/A2 Page 5 of 5 Copy
25、right 2002, Ford Global Technologies, Inc. TABLE 1 GUIDANCE TO PROPERTIES OF WSS-M21P37-A1/A2 COATING SYSTEMS Specification Color # Coats (a) Min. Thickness mm Min. Ct. Wt. g/m2 WZ 101 Torque Nm (b) WZ 101 Friction Coefficient m N.S.S. Hrs. Ferrous Corrosion N.S.S. Hrs. Zinc Oxidation Examples of Pa
26、rt Applications WSS-M21P37-A1 Silver 1 + 1 7 min, basecoat 8-10 typical 5 min, topcoat 5-8 typical 24 min, basecoat 8 min, topcoat Mean: 46-52 3 Sigma: 40-58 Mean: 0.15 0.01 3 Sigma: 0.15 0.03 840 240 Parts for exterior use requiring lubrication, externally threaded fasteners M6 and larger, stamping
27、s, brackets, clips, clamps, and door strikers. WSS-M21P37-A2 Silver 1 + 1 7 min, basecoat 8-10 typical 5 min, topcoat 5-8 typical 24 min, basecoat 8 min, topcoat Mean: 50-56 3 Sigma: 44-62 Mean: 0.165 0.01 3 Sigma: 0.165 0.03 240 120 Parts for exterior use requiring lubrication, internally threaded fasteners M6 and larger. NOTE: (a) NUMBER OF COATS ARE FOR DIP-SPIN APPLIED COATINGS AND MAY BE DIFFERENT DUE TO PROCESS. (b) BASED ON WZ101 TEST PROGRAM B.
