EXPLANATION
This test method simulates the corrosion process of non-ferrous metals (particularly alloys of lead and copper) in diesel lubricants. The corrosion process under investigation is believed to be induced primarily by inappropriate lubricant chemistry rather than lubricant degradation or contamination. This test method has been found to correlate with an extensive fleet database containing corrosion-induced cam and bearing failures.
TEST SUMMARY
Four metal specimens of copper, tin, lead, and phosphors bronze are immersed in a measured amount of engine oil. The oil at an elevated temperature is blown with air for a period of time. When the test is completed, the copper specimen and the stressed oil are examined to detect corrosion and corrosion products, respectively. A reference oil is tested with each group of tests to verify the test acceptability. The ASTM Test Monitoring Center (TMC) provides reference oils and an assessment of the test results obtained on these oils by the laboratory.
TEST PRECISION
Where I.P. is repeatability, and SI.P. is standard deviation.
Bias of this method is unknown at this time, but will be determined as more data are collected.