A copper corrosion test, is a performed in order to determine a lubricant’s capability to protect copper and copper-containing alloys from corrosion or staining. The test results are also indicative of a lubricant’s corrosion protection properties with other non-ferrous metals such as aluminum.
A cleansed copper trip is immersed in the test lubricant in a container, and this shall be exposed to a temperature of 100oC for 24 hours typically. The resulting appearance of the copper strip is visually compared against an ASTM copper strip corrosion standard, and the lubricant shall be graded according to its corrosion protection capability. A rating of 1a and 1b are deemed best, and succeeding numbers 2, 3, 4 denote weaker capabilities.
Such tests are important especially for bearing applications wherein copper or its alloys are used, as well as with metalworking fluids used for non-ferrous metals.