A finite element study of short cracks with different inclusion types under rolling contact fatigue load

摘要

A finite element study was performed of driving forces of short cracks at inclusions in bearing steel exposed to rolling contact load. Five inclusion configurations were considered, namely a pore, a manganese sulphide inclusion, a through-cracked alumina inclusion, an alumina inclusion which was uncracked but which could debond from the matrix and finally a titanium nitride inclusion. Short cracks were allowed to grow from the inclusions. The inclusions were 20μm in diameter. The cracks were allowed to grow from 2μm up to 8μm away from the inclusion interface into the matrix. The cracks were oriented 45° to the rolling contact plane in agreement with the experimental observations of so- called butterfly cracks in bearing steels.