Gradients of structure, phase composition and dislocation substructure of the rail heads made of hypereutectoid steel after operation

Abstract

The analysis of gradients of structure-phase states and dislocation substructure at a depth of up to 10 mm along the central axis of the head of DT400IK rails after 234.7 million tons passed on the Transbaikal railroad has been carried out using transmission electron microscopy methods. The formation of bending contours of extinction, indicating the elastically stressed state of the material, is revealed. Sources of curvaturetorsion of the crystal lattice are indicated: intra- and interphase boundaries. The mechanisms of destruction of lamellar pearlite (cutting by moving dislocations) and dissolution with displacement of carbon atoms to defects are considered.