Effect of Contact Stress on Rolling Friction and Wear Behavior of Wheel-rail Materials

The effect of contact stress on rolling friction and wear behavior of wheel/rail materials were investigated using a MMS-2A testing apparatus. The results showed that the rolling friction coefficient would increase with the increase of contact stress, which resulted in the aggravation of wheel/rail wear. The wear mass of wheel specimen was larger than that of rail specimen under the same contact stress condition. Furthermore, the surface damage of wheel specimen was more severe. With the increase of contact stress, the damage of wheel specimen changed from the plough with slight delamination to serious spalling damage. However, the plough with spalling phenomena was dominant for the damage of rail specimen. But the spalling damage of rail specimen was more slight than that of wheel specimen.