Effect of shoe braking on wear and fatigue damage of various railway wheel steels for high speed applications

Application of the Failure Assessment Diagram approach for contact fatigue damage evaluation in railway wheel steels

“…In order to show the predictive capacity of the method, the FAD was used to analyze the results of experimental rolling and sliding contact tests recently carried out by Mazzù et al 17 on discs extracted from railway wheels.…”

“…The tests were carried out by means of a bi‐disc machine on three different railway wheel steels used in Europe or in North America for shoe braked wheels: The steels were ER7 EN13262 (designated as HyperLOS® in Mazzù et al 17 ) and AAR Class B and AAR Class B+ (designated as SandLOS® in Mazzù et al 17 ). The chemical composition, the microstructural data, and the mechanical properties of the steels used in the FAD analysis were taken from previous papers of Faccoli et al 39,40 and are reported in Table 1.…”

“…The test parameters relevant for the FAD evaluation, referred to the steps of dry and wet contact between wheel and rail specimens, are summarized in Table 2 (where the sliding ratio is the ratio of the tangential speed to the mean rolling speed). The data referring to the initial contact between the wheel specimens and the brake‐block ones are not reported, as they are not relevant for the FAD evaluation; however, further details on the experiments are given in Mazzù et al 17 …”

“…The driving force is often related to an external fluid (rain or snow, for instance) that is entrapped inside the cracks and subsequently pressurized when the load passes over the crack mouth. Both the experience 15,16 and laboratory experiments 17,18 showed the detrimental effect of such environmental factor on the fatigue life. The damage in condition of elastic shakedown (e.g., with no cyclic plastic strain) is usually approached in terms of multiaxial fatigue 19,20 or crack propagation 21,22 .…”

Assessment of durability and reliability of ET41 series locomotive wheels based on laboratory tests

“…Since many rail vehicles are equipped with shoe brakes, the question of how their performance affects the wear of wheel tread is relevant. As shown in the study [15], only a small amount of cast iron from brake pads is transferred onto the wheel tread. Most of it is quickly removed when the wheel and track interact.…”