Scuffing Performance of M50 Bearing Steel Lubricated with a Gas Turbine Engine Oil at High Sliding Speeds

Abstract

The paper describes the results of scuffing tests carried out in a special high speed rig using M50 bearing steel rollers prepared to simulate the ball and raceway elements of gas turbine angular contact thrust bearings. The lubricant was Mobiljet2, a typical 5 cSt gas turbine engine oil, and sliding speeds of up to 30 m/s were simulated. It was found that the concept of “PV” (product of contact pressure and sliding speed) as a predictor of scuffing was not appropriate and a better indicator of failure under these conditions was the calculated value of oil film thickness in relation to the surface roughness of the rollers. In general the scuffing performance of M50 steel was found to be consistent with earlier work on ground and superfinished case-carburized steels when run with the same lubricant.