Micromechanical modeling of the elastic-viscoplastic behavior of polycrystalline steels

A self-consistent model developed to describe the elastic-viscoplastic beha vior of heterogeneous materials is applied to low carbon steels to simulate tensile tests at various strain rates in the low temperature range. The ch oice of crystalline laws implemented in the model is discussed through the viscoplastic flow rule and several strain-hardening laws. Comparisons betwe en three work-hardening models show that the account of dislocation annihil ation improves the results on simulations at large strains. The evolution o f the Lankford coefficients and texture development are also successfully s imulated. Some microstructural aspects of deformation such as the stored en ergy and the evolution of the flow rates are discussed. By including the di slocation density on each slip system as internal variable, intragranular h eterogeneities are underscored. (C) 2001 Elsevier Science Ltd. All rights r eserved.