A Review of wheel wear and rolling contact fatigue

Abstract
Railway wheels lives are limited by wear and the formation of rolling contact fatigue (RCF) damage. This review describes how the forces that cause wear and RCF on wheels are generated. It is demonstrated that shear stresses at and just below the surface are driven by forces generated during steady-state curving. Repeated applications of plastic shear stresses causes shear deformation of the material at and just below the wheel's surface. This can eventually lead to the formation and growth of surface cracks. Depending on the contact conditions, the surface cracks can develop into either wear or RCF. Tangential and normal forces, contact pressure, creepage, and the presence of fluid are important factors in determining the amount of wear and RCF. High strength wheel steels have been developed to withstand severe service loads. New materials and treatments are being developed to extend wheel life. The references quoted in this review show that RCF and wear of rails and wheels have been the subject of investigation for over 25 years. Several well-developed models exist for predicting wheel and rail wear. New models are emerging for rail RCF. These need to be further developed to be applicable to wheels.