The influence of residual technological stress and service heat loads on the strength of railway wheels

The article deals with the existing approaches to assessing the strength of railway wheels and the problems associated with forecasting actual spots of fatigue crack origination in operation. Solid-rolled railway wheels with a flat cone disk of standard design that have become a frequent practice in the Russian railway system are taken as an example. Calculations of the safety factor of fatigue resistance according to domestic and foreign standards have been carried out. The authors propose a procedure for assessing the wheel fatigue resistance to solve the above problems, taking into account the impact of residual technological stresses caused by heat treatment in the manufacturing process, followed by the repair of the rim, and service heat loads associated with the heating of the rim during braking, when the wheel interacts with blocks. Quantitative assessment of the impact of residual technological stresses and service heat loads on the strength of the wheels is presented. In conclusion the results of testing the computational methods described are presented, wheels of low-stress design with improved performance characteristics developed by the JSC «Vyksa Steel Works» taken as an example.