Fatigue Investigation on Railway Wheel Steel with White Etching Layer

Spalling is one common defect generally observed in railway wheels. The spalling phenomenon usually starts from the white etching layer (WEL) of the wheel due to cyclic loading. So far, the research work has not been systematically done on how the crack orientation influences the spalling behaviour. In our current study, the fatigue behaviours of the wheel steel with a surface crack under cyclic loading are investigated using extended finite element method. The significant parameters affecting the spalling behaviours such as the crack orientation and loadings are studied. Two key indices are used: the number of cycles required for the crack to reach the interface between the WEL and wheel steel material, and the crack propagation rate. The fatigue propagation trend in the WEL is validated by relevant experimental studies. Moreover, it is concluded from our results that a crack vertical to the surface has a greater propagation rate compared to other crack orientations.