Novel use of laser melting and optical pre-heat to control white etching layer formation on rail steels

Abstract

With the development of the railway industry, rail damage like Rolling Contact Fatigue (RCF) and White Etching Layer (WEL) are significant safety concerns. This study explores using lasers to replicate WELs on rail steels in a controlled, cost-efficient way in the laboratory. By optimising laser parameters like power, speed, and material, WELs similar to those in service rails were produced on R260, R350HT, and R400HT rail grades. The laser method yields precise WEL formation with thicknesses between 8 and 145 μm, offering better control and consistency than conventional methods. While thermally processed WELs are not fully representative of those formed by thermo-mechanical loading, they share similar hardness and size. This advancement supports further tribological testing and research on RCF-related damage.