Multistage dynamic damage and microstructural evolution of high-manganese steel under rolling-sliding contact conditions

Wear and fatigue are two critical challenges faced by railway frogs during service. However, existing studies have largely addressed these two damage mechanisms independently. In the present study, a twin-disc friction and wear test was employed to simulate the wear and rolling contact fatigue behavior of high-manganese steel used in railway frogs under service conditions. A detailed investigation was conducted to analyze the damage mechanisms and microstructural evolution of high-manganese steel over multiple test cycles. Results reveal that the damage evolution of high-manganese steel under rolling-sliding contact follows a dynamic and cyclic pattern. During this process, the surface-hardened layer undergoes repeated deformation strengthening, eventually leading to spalling and resulting in a distinct cyclic damage progression. This progression is primarily driven by the interplay between deformation strengthening, which enhances wear resistance, and the gradual accumulation of fatigue damage. As the surface-hardened layer spalls, the wear resistance deteriorates, exposing fresh layers to subsequent deformation strengthening and fatigue damage accumulation. This cyclical process culminates in the repeated occurrence of spalling damage. These findings offer valuable insights into the damage mechanisms of high-manganese steel under complex service conditions, providing a solid foundation for future research in this area.