1、 ENGINEERING MATERIAL SPECIFICATION Date Action Revisions 2011 02 24 N-STATUS No replacement named. No longer in use. G. Weber, NA 2007 08 31 Revised Revised numbering in 3.4 1989 08 09 Released NC00E00369150016 K. A. Gribble Printed copies are uncontrolled Copyright 2011, Ford Global Technologies,
2、LLC Page 1 of 3 CORROSION PROTECTIVE TUBE COATING, ESA-M21P20-A RESIN BONDED FLUOROPOLYMER NOT TO BE USED FOR NEW DESIGN 1. SCOPE This specification defines a resin bonded fluoropolymer coating which has excellent corrosion protection, adhesion, and formability qualities when applied over an electro
3、lytic or nonelectrolytic zinc or zinc/aluminum alloy plating. 2. APPLICATION This specification was released originally to provide additional corrosion protection to external surfaces of power steering gear turn lines. 3. REQUIREMENTS 3.1 STANDARD REQUIREMENTS FOR PRODUCTION MATERIALS Material suppl
4、iers and part producers must conform to the Companys Standard Requirements For Production Materials (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 Carb
5、on Steel Tubing ESF-M1A80-EA - Type 3 Construction SAE J527 - Brazed Double Wall LC Steel Tubing WSA-M1A308-A1/A2 - Tubing The above tubing shall be coated with either Zinc/Aluminum alloy per ESA-M1A270-A or Electrolytic zinc with a minimum coating thickness 0.025 mm. If necessary, a hexavalent chro
6、mium free conversion coating may be used over the zinc/aluminum alloy or the zinc plating to enhance the adhesion and corrosion resistance properties of the tube. 3.3 FILM PROPERTIES 3.3.1 Film Type The film shall consist of a single fluoropolymer coating or a fluoropolymer topcoat and primer system
7、. 3.3.2 Film Cure Must be sufficiently cured at the time of packing to withstand normal handling and shipping without marring. ENGINEERING MATERIAL SPECIFICATION ESA-M21P20-A Printed copies are uncontrolled Copyright 2011, Ford Global Technologies, LLC Page 2 of 3 3.3.3 Appearance The coating shall
8、be uniform in color and free from discontinuities. The coating shall be black in color unless otherwise specified on the engineering drawing. 3.3.4 Film Thickness, min 0.010 mm (Metallographic method) 3.4 RESISTANCE PROPERTIES 3.4.1 Adhesion No chipping or flaking Test Method: Scribe the tubing surf
9、ace to obtain a 3.2 mm square crosshatched pattern covering a minimum of 180 deg of circumference and 25 mm in length of tubing. Apply 3M #898 type adhesive tape firmly to the scribed surface. Remove tape slowly, applying an even consistent tension. 3.4.2 Salt Spray Evaluation After salt spray per A
10、STM B 117 for 3000 h the test samples shall show no more than 0.1% red rust per ASTM D 610 photographic standard No. 9. Test samples shall consist of two types, straight and bent tubes. Straight tubes shall be approximately 300 mm long. Bent tubes shall be bent in a U-shape with a radius equal to 3
11、times the diameter of the tube. 3.4.3 Water Resistance Properties, 240 h (FLTM BI 104-01) No rust or blistering 3.4.4 Gasoline Resistance Shall not blister or show any signs of softening or dulling when subjected to immersion in gasoline for 24 h at 23 +/- 2 C. 3.4.5 Hot Oil Resistance Shall not bli
12、ster or show any signs of softening or dulling when subjected to immersion in (SAE 10W 30) engine oil for 24 h at 66 +/- 3 C. 3.4.6 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 Conc
13、entrate, such as ESE-M97B43-A, for 24 h at 23 +/- 2 C. 3.4.7 Heat Resistance No chipping or flaking Heat in oven at 205 +/- 3 C for one hour. After cooling perform adhesion test per section 3.4.1. ENGINEERING MATERIAL SPECIFICATION ESA-M21P20-A Printed copies are uncontrolled Copyright 2011, Ford Gl
14、obal Technologies, LLC Page 3 of 3 3.4.8 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 h at 23 +/- 2 C. 3.4.9 Power Steering/Transmission Fluid Shall not blister or show any signs of softening o
15、r dulling when subjected to immersion in current factory fill power steering or transmission fluid for 24 h at 66 +/- 3 C. 4. GENERAL INFORMATION The information given below is provided for clarification and assistance in meeting the requirements of this specification. 4.2 Alternate methods of measuring coating thickness may be used during tube production but must be approved by the affected product engineering office.
