1、 FORD LABORATORY TEST METHOD BJ 007-05 Date Action Revisions 2000 08 31 Revised Editorial no technical change A. Cockman 1992 05 05 Printed copies are uncontrolled Page 1 of 3 Copyright 2000, Ford Global Te chnologies, Inc. CREVICE CORROSION TEST FOR BRAKE FLUIDS Application This test is used as a c
2、omparative evaluation of the tendency of brake fluids containing water and chloride ion to cause crevice corrosion on cast iron test samples. Apparatus Required Cast Iron Test Coupons 40 x 30 x 5 mm. Unless otherwise specified, test coupons are to be machined from the affected production parts. Solv
3、ent Standard solvent, naphtha or equivalent. Caution: These solvents are extremely flammable. Glass Rods 10 mm diameter by 40 mm lengths. 2 rods per test coupon. Abrasive Paper 600 and 400 grit. Steel Wire Uncoated 24 gauge SAE 1010 or equivalent, degreased. Desiccator Jaw 200 mm diameter or larger,
4、 without desiccant. Beakers 250 mL glass (3). Methyl Alcohol FORD LABORATORY TEST METHOD BJ 007-05 Page 2 of 3 Copyright 2000, Ford Global Technologies, Inc. Conditioning and Test Conditions All test values indicated herein are based on material conditioned in a controlled atmosphere of 23 +/ - 2 C
5、and 50 +/ - 5 % relative humidity for not less than 24 h prior to testing and tested under the same conditions unless ot herwise specified. Procedure For each test, three coupons shall be run in separate beakers. 1. Polish flat one face of each cast iron test coupon with 600 grit polishing paper. Po
6、lish the opposite side and edges with 400 grit paper. Degrease coupons with solvent, rinse with alcohol and dry. Coupons should be handled with forceps to prevent fingerprint contamination. 2. Place two pieces of glass rod on the smoother face of each test coupon and fasten with two single loops of
7、wire. Tighten wire only sufficiently to prevent movement of rods. See Figure 1. Glass rod must contact cast iron test coupon for full length of rod and coupon. 3. Place one assembly in each of three beakers, with the glass rods on top. Add to each beaker, 75 mL of test brake fluid which has been adj
8、usted to contain 4 % by weight water and 50 ppm chloride ion (added as sodium chloride). 4. Place the three beakers in the desiccator jaw (without desiccant) and cover. Maintain the jaw at 22 +/ - 3 C, undisturbed (stationary). 5 . Examine the test coupons every 24 hours for 21 days, unless otherwis
9、e specified in the Engineering Materials Specification. Examination may be conducted by viewing the crevice formed between the glass rods and the test coupon while the test coupon - rod assembly remains immersed in the fluid. A flashlight may aid in the examination. No evidence of corrosion should b
10、e detected at the crevice or elsewhere on the test coupon surface. Replace cover carefully after each examination to avoid disturbing the assemblies under test. Chemicals, materials, parts, and equipment referenced in this document must be used and handled properly. Each party is responsible for determining proper use and handling in its facilities. FORD LABORATORY TEST METHOD BJ 007-05 Page 3 of 3 Copyright 2000, Ford Global Technologies, Inc. CREVICE CORROSION TEST FOR BRAKE FLUIDS Test Coupon Rod Assembly Test Coupon Rod Assembly Figure 1
