Abstract:The rolling wear behavior of U75V quenched steel was investigated using wheel/rail simulation facility in heavy loading and light loading working conditions by changing the axle load under the premise of the Hertz simulation rules. The changes of hardness, plastic deformation and microstructure damage of the worn surface of rail specimens were analyzed by means of Vickers hardness tester, OM, SEM, etc. The results indicate that the wear loss of specimen is increased greatly with the increasing of axle load, and the plastic deformation of the specimen surface becomes more severe. The hardness of the specimen surface is increased remarkably after test, the corrugation is generated in the specimen surface at heavy loading, and the surface hardness in the peak and trough is higher than that at light loading. At heavy loading, the internal microstructure of the specimen is damaged seriously because of the lager stress condition, secondary even multiple cracks usually appear in the process of crack propagation, some cracks run through to the surface and eventually lead to the flaking off of surface material. At light loading, the fatigue crack usually extends along the direction of plastic flow, and the crack has no secondary crack regularly. Rolling contact fatigue is the major damage type of the specimens at light loading and heavy loading.