1、 ENGINEERING MATERIAL SPECIFICATION Date Action Revisions Rev 02 2014 02 21 Editorial See Summary of Revisions G. Weber, NA 2014 01 02 Revised Editorial updates See Summary of Revisions G. Weber, NA 2003 10 13 Activated D. Drobnich Controlled document at www.MATS Copyright 2014, Ford Global Technolo
2、gies, Inc. Page 1 of 5 FASTENER FINISH, ANIONIC EPOXY ELECTROCOAT, BLACK WSS-M21P41-A FASTENER FINISH, CATIONIC EPOXY ELECTROCOAT, BLACK WSS-M21P41-A2 1. SCOPE The materials defined by this specification are corrosion protective coatings applied anionically or cationically per supplier specification
3、s over various base coats over steel substrates. They consist of a zinc phosphate pretreatment, either an anodic epoxy electrocoat or a cathodic epoxy electrocoat, and an integrally cured torque modified post dip to provide consistent torque-tension control. Both processes provide enhanced corrosion
4、 resistance. Both processes are free of nickel, chromium, lead and cadmium. 2. APPLICATION These specifications were released for materials used as corrosion protective coatings for fasteners and other standard parts used throughout the vehicle. Since the processes do not induce hydrogen embrittleme
5、nt, these coating are suitable for high hardness parts. The cure temperature of the anodic system is 175 - 200 C and the cure temperature of the cathodic system is 175 - 200 C. These coatings shall not be specified if this temperature adversely affects the component being coated. 2.1 SERVICE TEMPERA
6、TURE The maximum continuous service temperature for A is 260 C. The maximum continuous service temperature for A2 is 260 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
7、 Materials (WSS-M99P1111-A) 3.2 LICENSEE APPLICATOR QUALITY REQUIREMENTS Applicators must follow coating manufacturer procedures and recommendations for chemical usage, equipment and processing. ENGINEERING MATERIAL SPECIFICATION WSS-M21P41-A/A2 Copyright 2014, Ford Global Technologies, Inc. Page 2
8、of 5 3.3 APPEARANCE 3.3.1 The anodic coating will be a flat black finish and free from discontinuities. 3.3.2 The cathodic coating will be a semi-gloss black finish free from discontinuities. 3.4 COATING THICKNESS A specific topcoat thickness is not specified. The minimum thickness shall be sufficie
9、nt to meet the corrosion requirements of the substrate material. A typical film build that exhibits the appropriate corrosion resistance for A is 7.5 to 15.0 micrometers in thickness and for A2 is 12.7 to 20.0 micrometers. Excessive coating thickness on threaded components may cause assembly concern
10、s. The general requirements of the Ford Worldwide Fastener Standards, Finish Specification WX100, Section 5 apply to this coating. 3.5 THREAD ACCEPTANCE REQUIREMENTS (WA900, WE900, WX100) For thread acceptance requirements see Ford Worldwide Fastener Standards WA900, WE900 and WX100. 3.6 CURING The
11、coating shall be cured 20 minutes at a metal temperature of 175 - 200 C (350 - 400 F) and shall not be used on materials that are adversely affected by these metal temperatures. This is consistent with both A and A2. 3.7 CLEANING Prior to coating, the substrate shall be free of oil, dirt, and simila
12、r foreign materials. If a cleaning process is necessary, it shall have no detrimental effect on the substrate, including freedom from embrittlement. See WSS-M99A3-A. All parts shall be zinc phosphated with a product to produce a minimum of 6 grams per square meter (600 mg/ft2) of coating on fastener
13、s. 3.8 ADHESION The coating shall withstand normal handling, storage, and installation without flaking or peeling or other loss of adhesion. 3.9 TORQUE TENSION (WZ101) The coatings shall meet the torque and friction coefficient specified in Table 1. ENGINEERING MATERIAL SPECIFICATION WSS-M21P41-A/A2
14、 Copyright 2014, Ford Global Technologies, Inc. Page 3 of 5 3.10 RESISTANCE PROPERTIES 3.10.1 Corrosion resistance (SAE/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 “Gen
15、eral 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 overall exceeding 0.1%, per ASTM D 610, grade 8, after the number of test h
16、ours specified in Table 1. 3.10.2 Water Resistance (A2 only) (FLTM Bl 104-01) Shall not blister or show any signs of red rust when subjected to immersion in water for 240 hours. This requirement is not applicable to A. 3.10.3 Gasoline Resistance (A2 only) Shall not blister or show any signs of softe
17、ning or dulling when subjected to immersion for 24 hours at 23 +/- 2 C in any commercially available 87 octane lead-free gasoline with 20% laboratory grade ethanol. This requirement is not applicable to A. 3.10.4 Hot Oil Resistance (A2 only) Shall not blister or show any signs of softening or dullin
18、g when subjected to immersion for 24 hours at 66 +/- 3 C in any commercially available engine oil meeting the latest API-ILSAC requirements. This requirement is not applicable to A. 3.10.5 Ethylene Glycol Resistance (A2 only) Shall not blister or show any signs of softening or dulling when subjected
19、 to immersion for 24 hours at 23 +/-2 C in any commercially available ethylene glycol-based engine coolant mixed 50/50 with water. This requirement is not applicable to A. 3.10.6 Brake Fluid Resistance (A2 only) Shall not blister or show any signs of softening or dulling when subjected to immersion
20、for 24 hours at 23 +/-2 C in DOT 3 or DOT 4 brake fluid. This requirement is not applicable to A. 3.10.7 Power Steering/Transmission Fluid (A2 only) Shall not blister or show any signs of softening or dulling when subjected to immersion for 24 hours at 66 +/-3 C in Mercon or Ford-branded power steer
21、ing and transmission fluid. This requirement is not applicable to A. ENGINEERING MATERIAL SPECIFICATION WSS-M21P41-A/A2 Copyright 2014, Ford Global Technologies, Inc. Page 4 of 5 3.11 ELECTRICAL CONDUCTIVITY This coating system is not recommended for electrical grounding applications 3.12 ULTRAVIOLE
22、T EXPOSURE (ASTM D 4587-01) These coating systems are not recommended for these applications. TABLE 1 GUIDANCE TO PROPERTIES OF WSS-M21P41-A/A2 COATING SYSTEMS Specification Color Typical Thickness m WZ 101 Torque Nm (a) WZ 101 Friction Coefficient N.S.S Hrs. Ferrous Corrosion N.S.S. Hrs. Zinc Oxida
23、tion Examples of Part Applications WSS-M21P41-A Black 7.6 to 15.0 Mean: 3541 3 Sigma: 32-44 Mean: .11 +/- .01 3 Sigma: .11 +/- .03 120 NA Parts for interior use externally threaded fasteners M4 and larger, stampings, brackets, clips and clamps. WSS-M21P41-A2 Black 12.5 to 20.0 Mean: 3541 3 Sigma: 32
24、-44 Mean: .11 +/- .01 3 Sigma: .11 +/- .03 240 NA Parts for interior and engine compartment use. All fasteners and stampings, clips clamps. NOTE: (a) BASED ON WZ101 TEST PROGRAM B. 4. GENERAL INFORMATION The information given below is provided for clarification and assistance in meeting the requirem
25、ents of these specifications. Contact for questions concerning Engineering Material Specifications. 4.1 WORLDWIDE FASTENER FINISHES When used for Worldwide Standard Parts, the Worldwide Fastener Finish Suffix as defined in Worldwide Fastener Finish Standard WX100 shall be specified as shown below:
26、WSS-M21P41-A S424 WSS-M21P41-A2 S451 5. SUMMARY OR REVISIONS 2014 02 21 Editorial updates: 3.10.3, 3.10.4, 3.10.5, 3.10.6, 3.10.7, removed obsolete material specifications and replaced with generic materials to use for testing. 2014 01 23 Editorial updates: Removed references to obsolete Ford materi
27、al specs in 3.10.4 and 3.10.5 Added details about test fluids and edited for readbility in 3.10.3 through 3.10.7 ENGINEERING MATERIAL SPECIFICATION WSS-M21P41-A/A2 Copyright 2014, Ford Global Technologies, Inc. Page 5 of 5 2014 01 02 Editorial updates: Removed corrosion protective coating from the title. Added references to the spec that this is fastener finish. Added WSS-M99P3-A in section 3.7 Added section 4
