On the wear and damage characteristics of rail material under low temperature environment condition

This study presents the wear and damage behaviours of U71Mn rail material with a friction pair of ER8 wheel material under different temperature conditions, which were explored using a rolling-sliding wear testing device. It turns out that, compared to those at 20 °C room temperature, the adhesion coefficient, wear rate and hardness all increase at low temperatures. Meanwhile, three types of damage mechanisms are proposed according to wear and rolling contact fatigue (RCF) behaviours under different temperature conditions: (a) room temperature (RT) damage mechanism, (b) ductile-brittle transition temperature (DBTT) damage mechanism, (c) below ductile-brittle transition temperature (BDBTT) damage mechanism. With the temperature decreasing from room to low temperature, the wear mechanism transforms from abrasive wear to adhesive wear and surface fatigue. Meanwhile, the rail material gradually becomes brittle and the subsurface damage at low temperature is more serious than that at room temperature. Furthermore, the subsurface damage at −15 °C is the worst. At low temperature, there is a wider size range of wear debris than that at room temperature.