3625A to evaluate the corrosion resistance of the coating to pitting. S1.11 Special Government Requirements: S1.11.1 Sampling—Part(s) plated for the US Government and Military use shall use MIL-STD-105 as the sampling plan. S1.11.2 Shot Peening—High strength steel part(s) processed for US Government and Military use shall be shot peened in accordance with MIL-S-13165 or rotary flap peened in accordance with MIL-R-81841. (see Note 6). S1.11.3 Packaging—Parts shall be packaged in accordance with Practice D 3951. APPENDIXES (Nonmandatory Information) X1. TABER ABRASER WEAR TEST METHOD X1.1 Scope X1.1.1 This test method will evaluate the resistance of the coating to abrasive wear. The test is performed by rotating a plated panel under rotating rubber wheels and weighing the panel after each 1000 cycles for weight loss. Duration of the test is 6000 cycles and it can be extended to 25 000 cycles for more complete results. NOTE X1.1—Variation in results have been attributed to the humidity in the laboratory and the storage conditions of the CS-10 wheels. Care should be taken to control the humidity between tests. X1.1.2 The results are variable between tests and therefore three plated test specimens should be tested to 6000 cycles each. The results should be averaged without the first 1000 cycles and the abrasion wear resistance is reported as the weight loss in mg/1000 cycles (Taber Wear Index). B 733 – 97 7 X1.2 Apparatus X1.2.1 Taber Abraser Wear Testing Unit—The unit must be capable of loading with 1000 g load and operating with a vacuum. X1.2.2 Abrasion Wheels— Use CS-10 (resilient rubber) Taber wheels. To reface the wheels use CS-11 discs from Taber. The hardness of CS-10 wheels can change with time and can effect the reproducibility of results (see Test Method D 4060). X1.2.3 Test Specimens— Test specimens shall be made from 20 gage CR steel 4 by 4 in. (100 by 100 by 1.3 mm) with a 0.250 (6.35 mm) hole in the center. Test specimens are available from Taber. X1.2.4 Analytical Balance—Scale which is capable of measuring to 150 g 6 0.1 mg. X1.3 Procedure X1.3.1 Plate three specimens with 0.001 in. (25 µm) of nickel phosphorus coating. X1.3.2 Wear test the specimens. For each of the three specimens complete the following steps: X1.3.2.1 Run the CS-10 wheels on the coating for 1000 cycles to remove any surface roughness. The wheels shall be loaded with 1000 g with a vacuum on high for the entire test. X1.3.2.2 Cool and weigh the specimen to the nearest 0.1 mg. X1.3.2.3 Dress the CS-10 wheels with a CS-11 disc for 50 cycles. X1.3.2.4 Abrasion test the coating with 1000 g load for 1000 cycles. X1.3.2.5 Repeat X1.3.2.2, X1.3.2.3 and X1.3.2.4 until a total of 6000 cycles have been accomplished for each specimen. X1.4 Reporting X1.4.1 Determine t |
