The influence of microstructure on the rolling contact fatigue of steel for high-speed-train wheel

Rolling contact fatigue (RCF) is an important concern for the durability of railroad wheels and rails, especially when considering high-speed trains. In this work, the effect of microstructures on the RCF of high-speed-railway was studied under a simulated train speed of 500 km/h. Two different carbon steel microstructures: spheroidized pearlite and lamellar pearlite, were achieved by different heat treatment. Results of rolling contact fatigue test demonstrated that the fatigue resistance of lamellar steel considerably exceeds that of spheroidized steel. The lamellar steel presented a more fragmentary surface but lower weight loss during the entire fatigue tests. Analysis of cross-section profiles of worn specimens suggests that cracks propagated near the surface of lamellar steel and may strengthen the fatigue resistance of the steel. Based on micro-indentation hardness data, it is suggested that greater energy dissipation induced by larger plastic deformation may also improve RCF resistance.