Modelling rail steel microstructure and its effect on crack initiation

The quality of rail steel has improved greatly in recent years and the material is more resistant to wear, plastic deformation and crack initiation; but track forces have also increased, and cracking of rails is a major concern. Different steel microstructures have different wear and rolling contact fatigue (RCF) behaviours when subject to cyclic, rolling–sliding, compressive contact. In order to capture the differences, it is necessary to model these at a microstructural level. This paper describes the development of microstructural models for incorporation into a wear and crack initiation model. A new mechanism is introduced which distinguishes RCF lives of pearlitic microstructures with different percentage volumes of pro-eutectoid ferrite.