Hardening mechanisms for rails metal during long-term operation

Abstract

A quantitative comparative analysis of the mechanisms of hardening of the surface layers of differentially hardened 100-m rails is carried out. It was based on structure formation, phase composition, defect substructure regularities revealed by the methods of modern physical materials science. The studies were carried out at different depths of up to 10 mm in the rail head along the central axis and along the axis of symmetry of the fillet in the initial state and after various periods of extremely long-term operation (passed tonnage of 691.8 and 1411 mln. tons brutto). The contributions due to the friction of the matrix lattice, interphase boundaries, dislocation substructure, presence of carbide particles, internal stress fields, solid-solution hardening of the pearlite component of the steel structure are estimated.