Formation of Gradient Structural-Phase States in the Head of Special-Purpose Rails during Operation

The structure, phase composition, and dislocation substructure in the head of long differentially quenched special-purpose rails made of E90KhAF steel after a passed gross tonnage of 187 mln t are analyzed. The formation of flexural extinction contours is observed, which indicates an elastic-stressed state in the material. The sources of lattice curvature–torsion are found to be intra- and interphase boundaries, and the mechanisms of destruction of cementite lamellae are determined.