ASTM D6557 Standard Test Method for Evaluation of Rust Preventive Characteristics of Automotive Engine Oils
4. Summary of Test Method
4.1 Multiple test tubes, each containing test oil and a specimen, are placed in a test tube rack that is attached to a mechanical shaker. The shaker speed and temperature are controlled.
4.2 Air and an acidic solution are continuously fed into each test tube over an 18 h period to create a corrosive environment.
4.3 The specimens are then removed, rinsed, and analyzed by an optical imaging system designed to quantify the antirust capability of each test oil.
5. Significance and Use
5.1 This bench test method was designed as a replacement for Test Method D5844. Test Method D5844 was designed to measure the ability of an engine oil to protect valve train components against rusting or corrosion under low temperature, short-trip service, and was correlated with vehicles in that type of service prior to 1978.
5.1.1 Correlation between these two test methods has been demonstrated for most, but not all, of the test oils evaluated.
