Microstructure evolution of railway pearlitic wheel steels under rolling-sliding contact loading

The objective of this work is to investigate the microstructure evolution of railway pearlitic wheel materials (ER7, CL60 and C-class) under a rolling-sliding contact loading. Firstly, microstructures of CL60 wheel steel at different depths from the strain-free matrix to the top surface were systematically investigated via laser scanning confocal microscope (LSCM), scanning electron microscopy (SEM), electron backscattered diffraction (EBSD), transmission electron microscopy (TEM) and X-ray diffraction (XRD). Secondly, the differences in microstructures of the top layers of those three types of wheel steels were explored. At last, the correlation between microstructure evolutions and their wear and rolling contact fatigue (RCF) behaviours was discussed. These information could provide a guide in development of premium railway wheel materials and choosing wheel materials.