Rolling Wear and Damage Behaviors between Three Kinds of Rail Materials and Wheel Material

The rolling wear and damage characteristics between three kinds of rails (U71Mn,PD3 and PG4) and AAR-B wheel material were investigated using a WR-1 wheel/rail rolling wear testing apparatus. The results show that three kinds of rail materials exhibited different microstructure. The hardness of rail material had no obvious effect on rolling friction coefficient of wheel/rail specimens. With an increase of rail hardness,the wear rate of rail specimen decreased and the wear rate of wheel specimen increased. Furthermore,total wear rate of wheel/rail specimens firstly decreased and then increased. The hardening rates of different rail specimens were tending to be the same with an increase of testing time. However,the hardening rates of wheel specimens obviously increaseed with an increase of rail hardness. The hardness ratios of rail/wheel specimens tended to be identical after a certain testing time. The rail material had an important effect on the surface damage morphology of wheel/rail specimens. With an increase of rail hardness,the surface ploughing of rail specimens became obvious. The surface spalling damage and plastic deformation of rail specimens alleviated. Furthermore,there was obvious fatigue crack on the rail specimens. However,the increase of hardness of rail material resulted in aggravating the spalling damage and plastic deformation of wheel specimens. The wheel/rail specimens exhibited obvious white layer and the white layer of wheel specimens were thicker than that of rail.