Influence of the microstructure of wheel materials on wear and rolling contact fatigue

Railway wheel–rail rolling contact inevitably causes wear and rolling contact fatigue (RCF) on the contact surface. This study evaluated the wear and RCF behavior of KS60 rail steel against two wheel materials: legacy rolled steel wheel (RSW) and standard ER8 wheel steel. Although both wheel materials showed similar mechanical properties, including tensile strength and hardness, ER8 exhibited a lower wear rate than RSW. This improvement was attributed to the lamellar pearlite structure of ER8, which enhanced wear resistance through significant work hardening. On the contact surface, ER8 showed considerable plastic deformation and minor pitting due to shallow crack propagation, whereas RSW exhibited severe spalling caused by limited plastic deformation and deeper crack growth.