Wheel Spalling Literature Review

Abstract

As a means of determining the conditions under which a patch of martensite (and eventually a spall) is formed on a wheel tread, the Wheel Defect Prevention Research Consortium (WDPRC) has conducted a review of wheel slide test reports and analytical models for the prediction of contact patch temperature due to wheel slide. The relative merits of the analytical models are discussed and applied to the known/assumed conditions, i.e., speed, axle load, and wheel/rail coefficients of friction (COF) for each of the wheel slide tests. The accuracy of the analytical models is evaluated with respect to test data under a variety of conditions from multiple sources. After selecting the most appropriate analytical model, wheel slide temperature predictions are given for empty cars at a variety of speeds and wheel/rail COF levels. It is concluded that the potential exists to create martensite on sliding wheels with almost any realistic combination of axle load, wheel slide duration, train speed, and wheel/rail adhesion level. Additionally, sources of wheel spalling are discussed with a focus on misapplied hand brakes and malfunctioning air brake systems. Multiple authors noted the presence of tread damage on one wheel of a wheelset with no damage at the corresponding circumferential location of the mate wheel. The accompanying theories to explain this seemingly counterintuitive finding are restated in this literature review. At the end of the paper, the actions of the WDPRC to reduce wheel spalling are briefly outlined.