Effect of strength coefficient of bainite on micromechanical deformation and failure behaviors of hot-rolled 590FB steel during uniaxial tension

Abstract

The effect of the strength coefficient (KB) of bainite on micromechanical deformation and failure behaviors of a hot-rolled 590MPa steel (590FB) during uniaxial tension was simulated using the elasto-plastic finite element method (FEM). The spatial distribution of the constituent phases was obtained using a phase identification technique based on optical microstructure. Empirical equations which depend on chemical composition were used to determine the stress-strain relationship of the constituent phases of the 590FB steel. The stress-strain partitioning and failure behavior were analyzed by increasing the KB of bainite. The elasto-plastic FEM results revealed that effective strain in the ferrite-bainite boundaries, and maximum principal stress in fibrous bainite, were enhanced as the KB increased. The elasto-plastic FEM results also demonstrated that the KB significantly affects the micromechanical deformation and failure behaviors of the hot-rolled 590FB steel during uniaxial tension.