Rolling contact fatigue of white etching layer: Part 2. Numerical results

White etching layer (WEL) is a surface metallurgical feature that is commonly present on rail when it is in service. An investigation of its behaviour under rolling sliding conditions has been conducted within the laboratory using twin disc testing. This has focussed on the rolling contact fatigue behaviour of the rail with the wear of both discs also being discussed. White etching layer has been simulated by spot welding, which creates a patch of martensite by heat treatment, and also by severe plastic deformation of the rail disc. This paper details the numerical results found from the crack growth and wear behaviour of the samples, while the accompanying paper describes the crack morphology. The results show that crack growth is dependant on the subsurface deformation of the pearlite, with longer cracks present for samples with a WEL than for those samples without, for the same number of cycles. The wear of the rail disc with a WEL is much lower than for samples without unless the surface spalls. In contrast, the wear of the wheel disc is much higher than for tests running against a disc without WEL.