Strengthening Mechanisms of Rail Steel under Compression

Abstract

The evolution of the structure–phase states and the 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 compressions of 15, 30, and 50%. Contributions to the strengthening caused by the friction of the matrix lattice, dislocation substructure, presence of carbide particles, internal stress fields, solid solution and substructural strengthening, and pearlite component of the steel structure were estimated. Using the adaptivity principle, which assumes the independent action of each of the strengthening mechanisms, the dependence of the rail steel strength on the degree of plastic deformation by compression was estimated. A comparative analysis of the stress–strain curves σ(ε) obtained experimentally and calculated theoretically was performed.