1、 ENGINEERING MATERIAL SPECIFICATION Date Action Revisions Rev. 4 2012 12 04 Revised Clarified the Fluid Resistance Requirements A.Wedepoh, FNA 2011 07 14 Revised Added PA612 option, see Summary of Revisions A.Wedepoh, FNA 1996 02 12 Activated J. Spencer Controlled document at www.MATS Copyright 2012
2、, Ford Global Technologies, LLC Page 1 of 8 CORROSION PROTECTIVE COATING, EXTRUDED WSS-M21P30-A1 POLYAMIDE OVER A ZINC/ALUMINIUM ALLOY COATED STEEL TUBE CORROSION PROTECTIVE COATING, EXTRUDED WSS-M21P30-A2 POLYAMIDE OVER ELECTRO-PLATED ZINC COATED STEEL TUBE CORROSION PROTECTIVE COATING, EXTRUDED WS
3、S-M21P30-A3 POLYAMIDE OVER HOT DIP ALUMINIZED STEEL TUBE CORROSION PROTECTIVE COATING, EXTRUDED WSS-M21P30-A4 CONDUCTIVE POLYAMIDE 12 OVER A ZINC/ALUMINUM ALLOY COATED STEEL TUBE 1. SCOPE The material defined by these specifications is an extruded polyamide 12 or polyamide 612 bonded to a primer tha
4、t has been applied to a zinc/aluminum alloy coated steel tube, electro-plated zinc coated steel or hot dip aluminized steel tube. 2. APPLICATION These specifications were released originally to specify the performance requirements for a secondary coating extruded over coated steel tube. The extruded
5、 coating provides additional protection for fuel lines, brake lines, power steering lines, and transmission oil cooler lines. 3. REQUIREMENTS 3.1 STANDARD REQUIREMENTS FOR PRODUCTION MATERIALS Material suppliers and part producers must conform to the Companys Standard Requirements For Production Mat
6、erials (WSS-M99P1111-A). 3.2 SUBSTRATE The substrate shall be low carbon steel butt welded or double wall brazed construction which conforms to one of the following specifications: SAE J526 Welded Low Carbon Steel Tubing SAE J527 Brazed Double Wall Low Carbon Steel Tubing WSA-M1A308-A1/A2 Tubing, si
7、ngle/double wall low carbon steel The above tubing shall be coated with the following systems: ENGINEERING MATERIAL SPECIFICATION WSS-M21P30-A1/A4 Copyright 2012, Ford Global Technologies, LLC Page 2 of 8 3.2.1 WSS-M21P30-A1 and A4 ESA-M1A270-A (zinc/aluminum alloy coated steel) 3.2.2 WSS-M21P30-A2
8、WSD-M1P85-A3 (electro-plated zinc coated steel) 3.2.3 WSS-M21P30-A3 WSD-M1A295-A1/A2/A3 (hot dipped aluminized steel) If necessary, a hexavalent chromium free conversion coating may be used over the coated steel systems to enhance the adhesion and corrosion resistance properties of the tube. 3.3 POL
9、YAMIDE PHYSICAL PROPERTIES 3.3.1 Polyamide 12 Melt Point (ASTM D3418) 3.3.1.1 WSS-M21P30-A1/A2/A3 170 - 185 C 3.3.1.2 WSS-M21P30-A4 173 - 179 C 3.3.2 Polyamide 612 Melt Point (ASTM D3418) 3.3.2.1 WSS-M21P30-A1/A2/A3 210- 221 C Note: Conductive PA612 per WSS-M21P30-A4 is unavailable at this time. 3.4
10、 FILM PROPERTIES 3.4.1 Topcoat Type The topcoat shall consist of polyamide 12 or polyamide 612 for A1, A2, and A3. Only polyamide 12 is allowed for A4. 3.4.2 Primer/Base Coat Must be sufficiently cured to enhance adhesion of the polyamide. An adhesion test must be part of the control plan. 3.4.3 App
11、earance The coating shall be uniform in color and free from discontinuities such as flow lines, pin holes, craters or abnormal roughness. The coating shall be black in color unless otherwise specified on Engineering Drawing. ENGINEERING MATERIAL SPECIFICATION WSS-M21P30-A1/A4 Copyright 2012, Ford Gl
12、obal Technologies, LLC Page 3 of 8 3.4.4 Film Thickness (FLTM BI 117-01 or an approved equivalent) 3.4.4.1 WSS-M21P30-A1 Polyamide, 170 m, min 3.4.4.2 WSS-M21P30-A2 Polyamide, 150 m, min 3.4.4.3 WSS-M21P30-A3 Polyamide, 120 m, min 3.4.4.4 WSS-M21P30-A4 Polyamide, 170 m, min 3.4.5 Film Properties Tub
13、e Size, nominal Coated Tube O.D., max 4.76 mm 5.21 mm 6.00 mm 6.45 mm 6.35 mm 6.80 mm 7.94 mm 8.39 mm 8.00 mm 8.45 mm 9.53 mm 9.97 mm 10.00 mm 10.45 mm 11.11 mm 11.59 mm 12.70 mm 13.17 mm 14.29 mm 14.76 mm 15.88 mm 16.35 mm 3.5 RESISTANCE PROPERTIES 3.5.1 Gravelometer/Salt Spray Evaluation 3.5.1.1 R
14、oom Temperature Gravelometer Test Method: Perform gravelometer testing per SAE J400 using five pints of gravel and salt spray per ASTM B 117. Tubing shall show no red rust after 2000 hours of exposure time at non-gravel impacted areas; red rust is allowable up to 1 mm from impacted areas. 3.5.1.2 Lo
15、w Temperature Gravelometer Test Method: The tube is to be conditioned at -40 C for a minimum of four hours prior to performing gravelometer test per SAE J400 using five pints of gravel. Sample should be impacted with gravel within 30 seconds of removal from freezer. Then salt spray per ASTM B 117. T
16、ubing shall show no red rust after 2000 hours of exposure time at non-gravel impacted areas; red rust is allowable up to 1 mm from impacted areas. ENGINEERING MATERIAL SPECIFICATION WSS-M21P30-A1/A4 Copyright 2012, Ford Global Technologies, LLC Page 4 of 8 3.5.2 Staggered knife/Salt Spray Evaluation
17、 Make six cuts, which are deep enough to expose the steel substrate, on each leg. The cuts can be either circumferential or parallel to the tube. Each circumferential cut will cover 60 of the tubes surface. Separate each cut by 1 cm. Start the second cut 1 cm above the end of first cut. Continue to
18、stagger the cuts in this matter. Alternatively, use two rows of parallel cuts. The first row will have 2 cm long cuts at 0, 120, and 240. The second row, separated by 2 cm from the first row, will have cuts at 60, 180, and 300 (see Figure 1). After the tubes have been cut, do the thermal cycling des
19、cribed below: Raise temperature to 125 C at a rate of 5 C/min. Hold at 125 C for 1 hour. Lower temperature to -40 C at a rate of 3 C/min. Hold at -40 C for two hours. This cycle is to be repeated six times. Then expose tubes to salt spray per ASTM B 117 for 1500 h. After exposure the polyamide extru
20、sion coating shall show no lifting or delamination. Red rust is allowed only at the knife cut. 3.5.3 Water Resistance Properties No rust or blistering. (FLTM BI 104-01, 240 h) 3.5.4 Fluid Resistance FLUID TYPE TEST TEMPERATURE EXPOSURE TIME Brake fluid 50 +/- 2 C 504 hours Power Steering/Transmissio
21、n 50 +/- 2 C 504 hours Motor oil (SAE 10W30) 50 +/- 2 C 504 hours Battery Acid (35 % by weight H2SO4) 23 +/- 2 C 504 hours Gasoline (unleaded) 23 +/- 2 C 504 hours Anti-Freeze 23 +/- 2 C 504 hours Windshield Washer 23 +/- 2 C 504 hours Test Method: The fluid samples will be divided into two groups.
22、Group 1. (Knife cut, Fluid Soak, Salt Spray, Burst) Step 1. Cut the tubes as described in section 3.5.2 at the locations shown in Figure 3 for all but the battery acid. This tube is left uncut because the acid reacts with the zinc aluminum coating. After removal from the fluids, the tubes will be ev
23、aluated for coating degradation. Step 2. Soak the tubes for the given time and temperatures in the fluids listed above Step 3. Expose tubes to 2000 hours salt spray per ASTM B117. Visually examine the parts for red rust. Step 4. Determine the burst pressure and compare it to the original. Group 2. (
24、Gravel, Fluid Soak, Salt Spray, Burst) ENGINEERING MATERIAL SPECIFICATION WSS-M21P30-A1/A4 Copyright 2012, Ford Global Technologies, LLC Page 5 of 8 Step 1. Gravelometer test the tubes as described in section 3.5.1.1. Step 2. Soak the tubes for the given time and temperatures in the fluids listed ab
25、ove Step 3. Expose tubes to 2000 hours salt spray per ASTM B117. Visually examine the parts for red rust. Step 4. Determine the burst pressure and compare it to the original. Requirements: Visual Inspection: After fluid soak, no lifting of the coating should be evident at knife cut under 10X magnifi
26、cation. The coating should not show any signs of degradation or loss of adhesion. Report any changes and contact Materials Engineering for review. Burst Pressure: All tubes must retain 80% of their original burst pressure. Corrosion Resistance: No red rust allowed at undamaged areas. Red rust allowe
27、d up to 1 mm away from knife cuts and gravel impacts 3.5.5 Electrical Resistance (WSS-M21P30-A4 only) 1 Mega Ohm Max (ESD DSTM11.13) 4. GENERAL INFORMATION This information given below is provided for clarification and assistance in meeting the requirements of this specification. Contact for questi
28、ons concerning Engineering Material Specifications. Example drawing callouts for the tube and coating materials for brake and fuel lines. Brake tube with Nylon 612 BRAZED DOUBLE WALL LOW CARBON STEEL TUBE PER SAE J527, NOMINAL O.D. X.XX. COAT WITH ZINC/ALUMINUM ALLOY PLUS EXTRUDED PA612 PER WSS-M21P
29、30-A1 MAXIMUM COATED TUBE O.D. PER WSS-M21P30-A1 Fuel tube with Nylon 612 WELDED LOW CARBON STEEL TUBE PER SAE J526, NOMINAL O.D. X.XX. COAT WITH ZINC/ALUMINUM ALLOY PLUS EXTRUDED PA612 PER WSS-M21P30-A1 5. SUMMARY OF REVISIONS 2012 12 04 Revised Fluid Resistance (3.5.4) to make test method and requ
30、irements more clear. 2011 07 14 Added PA612 material option due to PA12 shortage. Conductive PA612 still under development. Deleted Viscosity Range requirement Removed A1 and A2 (5 and 8 m) for the zinc plating per WSD-M1P85- A1/A2/A3 Added example drawing callouts. 2004 10 26 Added -A4, revised par
31、a 2.1, 2.3, 3.2.1, 3.3, 3.3.2; added 3.3.1.1, 3.3.1.2, 3.3.2.1, 3.3.2.2, 3.4.4.4 & 3.5.5ENGINEERING MATERIAL SPECIFICATION WSS-M21P30-A1/A4 Copyright 2012, Ford Global Technologies, LLC Page 6 of 8 FIGURE 1 STAGGERED KNIFE CUTS ENGINEERING MATERIAL SPECIFICATION WSS-M21P30-A1/A4 Copyright 2012, Ford Global Technologies, LLC Page 7 of 8 FIGURE 2 APPROXIMATE DIMENSIONS FOR FLUID RESISTANCE ENGINEERING MATERIAL SPECIFICATION WSS-M21P30-A1/A4 Copyright 2012, Ford Global Technologies, LLC Page 8 of 8 FIGURE 3 LOCATION OF STAGGERED CUTS
