COPPER CORROSION FROM LUBRICATING GREASE: D4048
EXPLANATION
This test method measures the tendency of lubricating grease to corrode copper under specific static conditions. It can help in predicting possible chemical attack on lubricating parts such as bearings containing copper or copper alloys. Such corrosion can cause premature bearing failures. However, no correlation with actual field service has been established. The test does not measure either the ability of the lubricant to inhibit copper corrosion caused by factors other than the lubricant itself nor does it measure the stability of the grease in the presence of copper.
TEST SUMMARY
A prepared copper strip is totally immersed in a sample of grease and heated in an oven or liquid bath at a specific temperature for a definite period of time. Commonly used conditions are 100° C for 24 h. At the end of this heating period, the strip is removed, washed, and compared with the ASTM copper strip corrosion standards.
TEST PRECISION
Because of the nature of this test, the precision of this test method was not obtained in accordance with standard ASTM protocol. The test has no bias.
