Strengthening mechanisms of rail steel under compression.

Abstract

The evolution of structural-phase states and dislocation substructure of rail steel under uniaxial compression to the degree of 50% was studied by transmission electron microscopy. The obtained data formed the basis for a quantitative analysis of the mechanisms of rail steel strengthening at degrees of deformation by compression 15, 30, 50%. Contributions to the strengthening caused by the friction of matrix lattice, dislocation substructure, presence of carbide particles, internal stress fields, solid solution and substructural strengthening, pearlite component of the steel structure are estimated. Using the adaptivity principle, which assumes the independent action of each of the strengthening mechanisms, the dependence of rail steel strength on the degree of plastic deformation by compression is estimated. A comparative analysis of the stress-strain curves σ(ε) obtained experimentally and calculated theoretically is performed