SwRI: Standard Test Methods ASTM D6594, ASTM D5968

	Metal coupons are immersed in engine oil then examined for corrosion.

The standard test methods for evaluating the corrosiveness of diesel engine oil, ASTM D6594 and ASTM D5968, are bench tests that evaluate diesel engine lubricants to determine their tendency to corrode alloys of lead and copper.

Some oils may inadequately inhibit the chemical attack of non-ferrous metals commonly used in bushings, bearings, cam followers, and oil coolers in diesel engines.

ASTM D6594 evaluates these corrosive tendencies at the higher temperatures (135°C) found in some engines, and ASTM D5968 uses an alternate test temperature (121°C). These test methods have been found to correlate with an extensive fleet database containing corrosion-induced cam and bearing failures.

 

	Four metal coupons, copper, lead, tin, and phosphor bronze, are used in the high-temperature corrosion bench test (HTCBT) procedure.

HTCBT Procedure

Four metal coupons including copper, lead, tin and phosphor bronze are immersed in a measured amount of engine oil. Air is passed through the oil at an elevated temperature for a period of time. When the test is completed, the coupons and stressed oil are examined to detect corrosion. Concentrations of copper, lead and tin must be below defined levels to meet individual specification requirements.

For more information about oil corrosiveness evaluation capabilities at SwRI or how you can contract with SwRI, please contact Janet Barker at jbarker@swri.org or (210) 522-6924.