Electrochemical Evaluation of Corrosivity in Turbine Engine Oils

This program involves the study of the factors associated with corrosion in turbine engine bearings. Turbine engine oil (MIL-L-23699) used in naval aircraft was found to absorb in excess of 2500 PPM of water at 25 °C and 100% RH. A mineral oil will absorb in the range of 400 to 500 PPM. This absorbed water causes bearings lubricated with MIL-L-23699 oil to be susceptible to corrosion. A probe which consists of a series of electrochemical galvanic cells is being used to measure corrosion currents developed in high humidity salt air environments. This probe was developed to measure the corrosivity of the naval shipboard environment. Preliminary corrosion current curves have been developed with a bare probe and a probe coated with MIL-L-23699 turbine oil. Studies will be made with MIL-L-23699 base oil and various additives one at a time to determine the effect of each additive in the fluid on corrosion.