Особливості виникнення та розвитку контактних руйнувань головок рейок

Abstract

Principal reasons of destruction of rail heads are considered in the article. Clarified, in the result of exploitation on the surface of rolling of rails there invoke longitudinal cracks, that weaken connection of superficial ball with rest volume of head's metal. This leads to the local crumpling on the side of the head edge and the initial stage of peel.Fissure of the surface layer of metal leads to disappear contact stresses in this place of the rail head , since the contact of the wheel and the rail at the corresponding points of the head becomes impossible.It is established that on the surface of the layer there is a hardening. In this connection, the yield stress increases accordingly. The degree of hardening is not the same in depth. The increased value of the yield point near the surface of rolling is replaced by the normal value of the yield point at a certain depth.That is, the upper layers of the railhead become non-uniform, in terms of the fluidity bounds.The calculations of the tense and deformed state of rail head were conducted in the zone of contact under simultaneous influence of normal and tangent constituent of pressure of wheels.