1、 ENGINEERING MATERIAL SPECIFICATION Material Name Specification Number Date Action Revisions 2002 06 11 Activated D. Drobnich Printed copies are uncontrolled Page 1 of 5 Copyright 2002, Ford Global Technologies, Inc. CORROSION PROTECTIVE COATING, ELECTROLYTIC WSS-M21P40-A1 ZINC PLATE, TRIVALENT CHRO
2、MATE, LUBRICATED ALUMINUM-RICH ORGANIC TOPCOAT, SILVER CORROSION PROTECTIVE COATING, MECHANICAL WSS-M21P40-A2 ZINC PLATE, TRIVALENT CHROMATE, LUBRICATED ALUMINUM-RICH ORGANIC TOPCOAT, SILVER 1. SCOPE The materials defined by these specifications are corrosion protective coatings over steel. They con
3、sist of an electrolytic or mechanical zinc plate, a hexavalent chromium free conversion coating, and an integrally lubricated aluminum-rich topcoat. This coating system provides enhanced corrosion protection, color and/or consistent torque-tension control. They are free of hexavalent chromium, nicke
4、l, lead and cadmium. 2. APPLICATION These specifications were released originally for materials used for corrosion protective coatings over steel. They are suitable for externally and internally threaded fasteners and non-threaded parts where a high level of corrosion is required. The cure temperatu
5、re for the aluminum rich topcoat is 200 to 220 C. These coatings shall not be specified if this temperature adversely affects the component being coated. These coatings provide good bi-metallic corrosion resistance when in contact with aluminum. They should not be applied to parts in contact with un
6、coated copper, magnesium or stainless steel surfaces. 2.1 SERVICE TEMPERATURE The maximum continuous service temperature resistance of A1 and A2 is 260 C. 3. REQUIREMENTS 3.1 STANDARD REQUIREMENTS FOR PRODUCTION MATERIALS Material suppliers and part producers must conform to the Companys Standard Re
7、quirements For Production Materials (WSS-M99P1111-A). ENGINEERING MATERIAL SPECIFICATION WSS- M21P40-A1/A2 Page 2 of 5 Copyright 2002, Ford Global Technologies, Inc. 3.2 LICENSEE APPLICATOR QUALITY REQUIREMENTS Applicators must follow coating manufacturer procedures and recommendations for chemical
8、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 performance of the coated parts. 3.3.2 Cleaning Prior to coating, the parts shall be free of oil, sc
9、ale, and similar foreign materials. The cleaning process shall have no detrimental effect on the substrate, including freedom from embrittlement. 3.3.3 Curing The topcoat is typically cured at 200 to 220 C and shall not be used on materials that are adversely affected by these material temperatures.
10、 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 with a Watmans No.41 filter paper, or equivalent, and applying hand pressure for 5 to 10 seconds, there shall b
11、e 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 The coating shall be uniform in color and free from discontinuities when viewed without magnification. 3.3.6 Sto
12、rage 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. ENGINEERING MATERIAL SPECIFICATION WSS- M21P40-A1/A2 Page 3 of 5 Copyright 2002, Ford Global Technologies, Inc. 3.4 ADHES
13、ION 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 blistering, peeling, flaking or coating which can be removed by a filament type tape, such as 3M No. 898-2. The
14、 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 (SAE/USCAR-1, ASTM B 117, ASTM D 610, WX100) Fasteners shall be tested and evaluated in accordance with SAE/USCAR-
15、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 ferrous corrosion overal
16、l 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 subjected to immersion in water for 240 hours. 3.5.3 Gasoline Resistance Shall not blister or show any signs of
17、 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 dulling when subjected to immersion in engine oil (SAE 10W30 per WSE-M2C903-A2 or equivalent) for 24 hours at 66
18、 +/- 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 concentrate (WSE-M97B44-B or equivalent) for 24 hours at 23 +/- 2 C. ENGINEERING MATERIAL SPECIFICATION WSS- M21P40-A1/A
19、2 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 approved brake fluid for 24 hours at 23 +/- 2 C. 3.5.7 Power Steering/Transmission Fluid Shall not blister or
20、 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 PLATING THICKNESS, MIN. 6 MICROMETRES (ASTM B 659, ASTM B 487) The plating thickness requirement identified above represents the minimum v
21、alue and applies to all significant surfaces unless otherwise specified on the Engineering Drawing. In case of dispute, the thickness measurement umpire method shall be metallographic sectioning per ASTM B 487. 3.7 TOP COAT THICKNESS AND WEIGHT (MASS) (ASTM B 568/ISO 3497, ASTM B 499/ISO 2178) The t
22、op coat thickness and minimum coating weight are given in Table 1. The top coat thickness should be measured on flat surfaces using a magnetic induction thickness instrument (ASTM B 499/ISO 2178) or by calibrated X-ray fluorescence spectroscopy (ASTM B 568/ISO 3497), and should be based on an averag
23、e of at least ten measurements. 3.8 THREAD ACCEPTANCE REQUIREMENTS (WA900, WE900, WX100) For thread acceptance requirements see Ford Worldwide Fastener Standards WA900, WE900 and WX100. 3.9 TORQUE-TENSION (WZ101) The coating shall meet the required torque and friction coefficient specified in Table
24、1. ENGINEERING MATERIAL SPECIFICATION WSS- M21P40-A1/A2 Page 5 of 5 Copyright 2002, Ford Global Technologies, Inc. TABLE 1 GUIDANCE TO PROPERTIES OF WSS-M21P40-A1/A2 COATING SYSTEMS Specification Color # Coats (a) Min. Thickness m Min. Ct. Wt. g/m2WZ 101 Torque Nm (b) WZ 101 Friction Coefficient N.S
25、.S. Hrs. Ferrous Corrosion N.S.S. Hrs. Zinc Oxidation Examples of Part Applications WSS- M21P40-A1 Silver 1 + 1 6 min, elect. zinc plate 6-8 typical 5 min, topcoat 5-8 typical 43 min, zinc plate 8 min, topcoat Mean: 46-52 3 Sigma: 40-58 Mean: 0.150.01 3 Sigma: 0.150.03 840 240 Parts for exterior use
26、, externally and internally threaded fasteners M6 and larger, and parts with a hardness not in excess of 39 HRC. WSS-M21P40-A2 Silver 1 + 1 6 min, mech. zinc plate 6-8 typical 5 min, topcoat 5-8 typical 35 min, zinc plate 8 min, topcoat Mean: 46-52 3 Sigma: 40-58 Mean: 0.150.01 3 Sigma: 0.150.03 840 240 Parts for exterior use, externally and internally threaded fasteners M6 and larger, and parts with a hardness in excess of 39 HRC. 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.
