BT-10 Navistar Oxidation Corrosion Test
Lubricant oxidation may cause additive depletion, viscosity changes, sludge formation, sediment and acid formation, and corrosion of system metals. Oxidation is accelerated in the presence of heat, oxygen or metal ions. This test determines how lubricating fluids and metals in those fluids change with elevated temperatures in the presence of air.
The metal specimens are prepared as per the method, placed in it the oxidation-corrosion tube and the test fluid is added. The system is brought to the test temperature and air is bubbled through it for the test time. At test termination, the metals are cleaned and the fluid is examined. Reported are changes in the metal (weight loss and residue deposited on each metal), fluid characteristics: (change in precipitation number (ASTM D91) and change in viscosity (ASTM D445)); and the appearance of the oxidation tube.