Analysing the rolling contact damage behavior of a high-speed wheel tread-A case study

This study presents the rolling contact fatigue (RCF) mechanism and damage behavior of the motor wheel and trailer wheel of a high-speed EMU operating over 1.73 million kilometers in a wind and sand environment in Northwest China. The results indicate that the profile hardness of the wheel decreases with increasing distance from the surface and finally stabilizes. Within a certain distance from the surface, the hardness of the flange root changes sharply. The surface of the tread hardens, the hardness value increases, and the variation law is similar to that of the plastic deformation of the profile. The wheel treads of the motor and trailer suffer more serious damage, such as cracks, spalling pits, dents and pitting on the surface. The profile damage is mainly charac-terized by long and thin layered cracks and branch cracks. Cracks located at the root of the flange and outside of the nominal circle tend to propagate toward the inside of the flange and form branch cracks and delamination cracks, which may cause multiple cracks to penetrate each other to form spalling.