Failure analysis of the elements of a forced-in joint operating in rotational bending conditions

Abstract

Forced-in joints, especially those operating in harsh conditions, are susceptible to premature damage and wear. Such a situation may lead to incidents with severe consequences. Microcracks or changes in the structure of the joint elements may contribute to the development of fatigue cracks and unexpected damage during operation. In this work, typical damage and wear which may be observed at a shaft and sleeve surface made of structural materials used in production of the wheel and axle of the rail vehicle axle set. That damage and wear have come into being as a result of both the pressing process and operation. After the pressing process, the surface of the elements was distinguished by typical traces such as scratches running long the pressing direction, by dents and micropulluots. Brown fretting wear traces at a small distance from the joint edges have been noted at the shaft and sleeve surfaces subjected to fatigue tests through the operation of the rotational bending moment. Fretting wear comprises, to a large extent, material build-ups which have come into being as a result of adhesion-related processes. During operation, those build-ups underwent plastic deformation and oxidation.