A microstructure-based analysis for cyclic plasticity of dual-phase pearlitic rail steels

摘要

Based on the assumption that a representative element of a pearlitic steel is an aggregate of numerous spherical pearlitic colonies with randomly distributed orientations, and that each colony is com- posed of many parallel fine lamellas of ferrite and cementite, a description for the dual-phase pearlitic steel is obtained by making use of a microstructure-based constitutive equation for a single dual-phase pearlitic colony and the Hill's self-consistent scheme. The elastoplastic response of dual-phase pearlitic steel BS11 subjected to asymmetrically cyclic loading is analyzed, and a comparison with the experimental results shows satisfacto- ry agreement. The non-proportional cyclic plasticity of BS11 is also analyzed, in which stress develops along a semi-circle in a biaxial tension/compression and shear stress plane, as is typically experienced by the sur- face elements in rolling and sliding contact.