Damage Mechanism of Railway Wheels under Condition with Angle of Attack

There will generate an angle of attack between railway wheels and rails under curve negotiating and hunting conditions. With the aim of investigating the damage mechanisms of railway wheels under condition with angle of attack, the rolling contact fatigue test of simulate wheel was performed using a JD-1 wheel/rail simulation facility. The results indicate that different damage mechanism occurred at the different region of wheel specimen, and the regions were divided into three parts, i.e. the plastic accumulation region, the fatigue region and the worn region. Drastic changing in stress and the stress direction was from the high stress region to the lower one, it world appear the material accumulation which led to fatigue crack initiation. Rolling contact fatigue cracks initiated at surface or sub-surface in the fatigue region, and the grains of wheel material became elongated obviously under high stress, showing fibrous shape in cross section.