Influence of wheel/rail tangential traction force on thermal cracking of railway wheels

In terms of the durability of carbon steel railway wheels, so-called tread thermal cracking, one of severe damages on the tread surface, was investigated to understand the dominating factor and the countermeasures against thereto. Based on the temperature conditions predicted by material investigation and numerical analysis, the residual stress state during tread braking and after cooling was estimated. On the basis of the analysis on the distribution morphology of the cracks, we have focused on the wheel/rail tangential traction force as a source of the sequential external force imposed on all circumferences of wheel tread. A series of full-scale experiments were carried out to clarify the influence of residual stress and tangential force on tread thermal cracking. The wheel/rail tangential force and the localized tensile residual stress caused by localized heating, rather than wheel weight, largely affect the thermal cracking.