Relating Humidity Cabinet Life of Lubricants to Their Service Life

In the past the results obtained from humidity cabinet corrosion tests have been useful for comparing one protective material with another, but of little value for predicting the protective life of any given material under atmospheric exposure conditions. A corrosivity factor, arbitrarily developed, has been found invalid. A method has been developed from experimental data by which the humidity cabinet life of a lubricant may be used to predict its protective life on steel when exposed to the atmosphere. This method is expressed mathematically as a function of temperature, humidity, and protective life (time). It is applicable for world-wide use by using local temperature and humidity data for the location under consideration. The same general equation appears to be applicable for any lubricant. Each lubricant has its own constants, which must be determined from experimental data. The constants for two lubricants have been determined. Contributed by the ASLE Technical Committee on Properties of Lubricants...