Structural Phase State of the Metal of a Rail with an Internal Crack after Long-Term Operation

During operation, various physical and mechanical processes occur in the metal of the rails under cyclic force action over time: plastic deformation of the rail rolling surface, the formation of internal and surface cracks, changes in residual stresses, etc. As a result, the mechanical characteristics degrade and the performance of the rails decreases. A microstructural analysis of the cross-section surface of two rails with internal cracks—longitudinal and transverse ones—has been performed. The rail samples were taken out of attendance after many years of service. Fractographic analysis of the crack surface and the surrounding material indicates a significant degradation of the physical and mechanical properties of the rail steel and intensive structure formation during long-term operation of the rails.