1、 FORD LABORATORY TEST METHOD BQ 004-01 Date Action Revisions 2000 08 07 Editorial no technical change A. Cockman 1992 08 04 Printed copies are uncontrolled Page 1 of 4 Copyright 2000, Ford Global Technologies, Inc. CORRODKOTE TEST FOR PLATED PARTS Application This procedure is used to determine the
2、corrosion resistance of plated parts. It is used primarily for copper/nickel/chromium and nickel/chromium electro - plated parts. Apparatus Humidity Cabinet Refer to ASTM B 117 Appendix “Construction of Apparatus.“ The test chamber shall be at least 0.5 m 3 capacity and preferably larger to permit a
3、dequate control of the environment. It should be large enough to test entire (uncut) parts. Thickness Gage A Gardner or equivalent Wet Film Thickness Gage range 0 - 4 mils is used for checking the thickness of the corrodkote coating. Evaluation Grid A transparent grid* of pliable plastic, marked off
4、 in 6.4 mm squares, is used to determine the amount of corrosion on the tes t specimens. The standard grid shall be rectangular in shape and shall contain 100 6.4 mm squares (the lines marking the squares shall not exceed 0.13 mm in width). The percent of corrosion is determined by placing the grid
5、in firm contact with the plate d surface of the test specimen and counting the grid units containing corrosion defects. * A convenient grid size for overall evaluation is 64 x 64 mm. Glass Plate 64 x 64 mm or larger convenient size. Paint Brush Illumination for Evaluating Test Results Fluorescent da
6、ylight white. 645 - 860 lux (60 - 80 ft candles) at area where examination of part is being performed. Materials Required Ferris Chloride FeCl 3 6H 2 O, lump, reagent grade. FORD LABORATORY TEST METHOD BQ 004-01 Page 2 of 4 Copyright 2000, Ford Global Technologies, Inc. Cupric Nitrate Cu(NO) 3 3H 2
7、O, reagent grade. Ammonium Chloride NH 4 C l, reagent grade. Kaolin EPK - A/S Powdered Kaolin. Note: Laboratory grade is NOT satisfactory. Source: Feldspar Corporation P.O. Box 99 Spruce Pine, NC 20777 Distilled or Deionized Water 20 Micromhos/cm at 25 C maximum conductivity (ASTM D 1125). Soft Synt
8、hetic Sponge Soft Paper Towels Solvent Such as alcohol, acetone or petroleum ether. Caution: Low flash point. Refer to Industrial Hygiene for health and safety comments. Tripoli or equivalent mild abrasive. Users of this test method should en sure that they comply with all governmental and (if a For
9、d Motor Company activity) Company regulations regarding the handling and use of the above materials. Company users should contact their industrial hygiene and environmental activities for appropriat e precautions. Preparation of Slurry Refer to ASTM B 380 - “Corrodkote Slurry“ for preparation of slu
10、rry. (Refer to note in “Materials Required“ section.) Note: Some kaolins may require the addition of slightly more water than the prescribed 300 mL to obtain the proper viscosity for brushing. If the paste, when mixed as specified, is too thick, add distilled water for a few mils at a time, mixing t
11、horoughly between additions until the right consistency is obtained to secure the proper wet film thickne ss. Conditioning and Test Conditions All test values indicated herein are based on material conditioned in a controlled atmosphere of 23 +/ - 2 C and 50 +/ - 5 % relative humidity for not less t
12、han 24 h prior to testing and tested under the same condi tions unless otherwise specified. FORD LABORATORY TEST METHOD BQ 004-01 Page 3 of 4 Copyright 2000, Ford Global Technologies, Inc. Procedure 1. Preparation of Test Specimens - Refer to ASTM B 380 - “Preparation of Test Specimens.“ In addition
13、, when testing steel parts/panels, coat a glass plate in order to verify that the paste contains no contami nants that form a rust color in the humidity cabinet. Note: Wet film thickness of corrodkote past shall be 0.025 - 0.075 mm (with 0.050 mm preferred). 2. Position of Specimens During Test - Re
14、fer to ASTM B 380 - “Position of Specimens During Test.“ 3. Humidity Cabinet Conditions - The relative humidity shall be maintained at 95 - 100 %. There shall be no condensation of moisture on the test specimens. The cabinet shall be maintained at 38 +/ - 1 C and the saturator tower at 43 +/ - 1 C.
15、4. Test Cycle - Refer to ASTM B 380. 5. Period of Test - The time and number of cycles shall be specified by the applicable Engineering Material Specification or Engineering Print. 6. Cleaning of Test Specimens - Upon removal of the specimens from the humidity cabine t, using the soft synthetic spon
16、ge, wash the specimens under running water to remove the corrodkote coating. Wipe dry with a soft paper towel. Note: Prior to preparing the surface to determine the size of a specimen corrosion spot, do not use an abrasiv e material on the specimen to remove corrosion products unless the corrosion a
17、rea is redeveloped as described in ASTM B 380 “Cleaning of Tested Specimens.“ 7. Evaluate as follows: Hold the part approximately 300 mm from the eye in a room lighted with day light white fluorescent light and examine for the following concerns: red rust, blisters, white corrosion, pits, and cracks
18、. The part should be set against a white background with 645 - 800 lux illumination in the area where examination is being performed. a. Lay the transparent grid containing 6.4 mm squares over the part and count the squares containing one or more concerns. Do this for the entire significant surface.
19、 Note: Fine blisters, etc. may be seen through the grid only if it is in close contact with the surface of the part. Fingerprints and light soil may be removed from the grid by washing with mild soap and wiping dry with a soft paper towel. Divide the number of 6.4 mm squares containing concerns by t
20、he total number of squares covering the plated surface. The figure multiplied by 100 = percent overall corrosion. FORD LABORATORY TEST METHOD BQ 004-01 Page 4 of 4 Copyright 2000, Ford Global Technologies, Inc. Example: If the part has 1650 6.4 mm squares and the number of squares containing one or
21、more concerns was 70, then 70 x 100 = 4.2 % overall corrosion 1650 b. Report localiz ed corrosion as follows: Lay the 64 x 64 mm transparent grid (100 6.4 mm squares) over the part where the greatest number of corrosion spots are found. Count the squares containing one or more concerns. Squares cont
22、aining corrosion spots X 100 = % loca lized corrosion 100 Note: On die cast parts, the white corrosion products may be larger than the actual blister or hole (i.e. pit) in the plate. Only the diameter of the corrosion spot is measured when the maximum allowable size is specified. I f in doubt as to
23、the actual size of the corrosion spot, clean the part with light rubbing, using tripoli polishing powder or similar mild abrasive, redevelop the corrosion area (as listed in ASTM B 380 “Cleaning of Test Specimens“) and again examine. Do n ot scour the part if the part has already failed to meet the overall or localized corrosion limits. 8. Report as per ASTM B 380 - “Report.“ Chemicals, materials, parts, and equipment referenced in this document must be used and handled properly. Each p arty is responsible for determining proper use and handling in its facilities.
