Investigation into the mechanisms of Corrosion-Induced rolling contact fatigue crack initiation and propagation in pearlitic rails

Corrosion stands as a pivotal causative agent for the initiation and propagation of rolling contact fatigue (RCF) cracks on rail surfaces. This study aims to scientifically delineate the corrosion fatigue behavior of U75V rails. The study identifies the presence of oxidative corrosion and graphitization on the rail surface. Carbides near the rail surface cause stress concentration, reducing the rail's RCF residence. Oxide corrosion engenders internal oxide inclusions within cracks, expediting RCF crack propagation. Furthermore, grain refinement and discordant deformation between soft and hard grains near the rail surface give rise to sub-surface microporosity and microcracking. These findings advance our comprehension of rail RCF and offer insights for guiding rail maintenance and informing new rail design strategies.