Wear in a high-speed roller bearing

AbstractWear phenomena in a worn high-speed roller bearing made of ALSI 52100 steel were studied using metallography, electron-probe microanalysis, and microhardness measurements. Friction layers related to thermal effects were observed in the surface material of the bearing components, as already reported for sliding surfaces. A hard, martensitic, light-etching layer was observed on the surfaces of the rollers and the outer-ring raceway, while a soft dark-etching layer was observed on the surface of the inner-ring raceway. Failure of the bearing was due to excessive wear of the inner-ring raceway. Thus it was concluded that the most important harmful effect of the observed microstructural changes was to upset the hardness balance between roller surfaces and inner-ring raceway, leading to machining of the inner-ring raceway by the rollers. Surface pitting and other phenomena relating to rolling-contact fatigue were not significant wear mechanisms.