The influence of hydrogen on rolling contact fatigue life and its improvement

Abstract

Bearings for automotive powertrains sometimes suffer flaking damage that unexpectedly shortens their life due to peculiar microstructural changes at their subsurface. In this paper, based on various experiments, we describe the characteristics and cause of such flaking and a way to prevent it. The experimental results suggest that this flaking is a kind of hydrogen embrittlement caused by the diffusion of hydrogen into the steel due to the decomposition of the lubricant. Controlling this diffusion of hydrogen can effectively prevent this flaking and provide long bearing life.