ISO/DIS 25949

Petroleum and related products — Determination of the scuffing temperature of lubricants — High-frequency, linear-oscillation (SRV-type) test machine ISO/DIS 25949

Scope

This test method covers the determination of a scuffing temperature of lubricants at prescribed conditions and the retention of friction over temperature step increases in a roller-on-disk (flat) geometry when subjected to high-frequency, linear oscillation motion. This test method is executed under constant load, oscillating frequency and stroke in a SRV-type test machine. The evolution of coefficient of friction of lubricating oils as function of temperature is recorded and assessed.
In tribometric tests, scuffing is so far initiated by a.) constant load step increases or b.) constant Hertzian contact stress step increases, as in FZG. This proposed test method determines the upper temperature for operating a lubricant and can also be used to determine the ability of a non-EP lubricant to protect against scuffing with increasing temperature.