Comparison of microstructure changes induced in two pearlitic rail steels subjected to a full-scale wheel/rail contact rig test

摘要

This study focused on the comparison of the microstructure changes induced in two pearlitic rail steels subjected to full-scale wheel-rail contact rig tests (DB Systemtechnik, Germany): a conventional R260 steel grade and a heat-treated premium R370CrHT rail grade (also known as MHH400). The total loading of the wheel/rail contact rig test was computed to be 2.4 million gross tons but aimed at reproducing large deformations caused by loadings around 100 million gross tons into the materials. The description of the microstructure showed the ability of the rig to reproduce large loadings. Through the coupling of optical and SEM observations, EBSD measurements and hardness tests along the depths of the tested rails, it was shown that the plastic deformation was much more confined in R370CrHT than in R260. This thorough comparison of the microstructure changes will help the building of wear scenarios.