ASTM D6594

The ASTM D6594 test method covers testing diesel
engine lubricants to determine their tendency to corrode
various metals, specifically alloys of lead and copper
commonly used in cam followers and bearings. Four
metal specimens of copper, lead, tin, and phosphor
bronze are immersed in a measured amount of engine
oil. The oil, at an elevated temperature, 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
test acceptability. This test also known as ASTM D6594
or High Temperature Corrosion Bench Test (HTCBT), is
one of the required laboratory tests in the new API CK4
and API FA4 Service Categories