Microstructure and cyclic deformation behavior of wheel and tire steels intechnically relevant heat treatments

The present developments of rail-mounted traffic aim at higher speeds in th e passenger and higher axle load in the freight traffic. As a consequence, a substantial increase of the loading of the wheels has to be regarded. Geo metric changes at wheels and rails cause high cyclic loading in the dynamic system wheel/rail as a function of the course rate [1-6]. Since for wheel steels only a few systematic investigations of the fatigue behavior are ava ilable so far, the actual investigations concentrate on the relation betwee n the local microstructure and the description of the fatigue behavior of h ighly stressed wheel steels. As test materials monoblock wheel steels and t ire steels were selected in accordance with UIC specification in technicall y relevant heat treatment conditions. The cyclic deformation behavior is ch aracterized and evaluated by stress-strain hysteresis as well as thermometr ical and electrical measurements.