Micromechanical modeling of cleavage fracture for a ferritic-pearlitic steel

Abstract

Despite efficient computational capability of phenomenological macromechanical models to predict cleavage fracture, they still lack microstructure sensitive information for material design. Therefore, a microstructure-based micromechanical modeling approach is proposed to predict cleavage fracture for a steel of grade AISI 1045 at different stress states. For the micromechanical modeling, virtual experiments are performed on an artificial microstructure model to derive the plasticity and cleavage damage initiation strain for the investigated material at −196 °C. The predicted microcrack initiation strains of cleavage fracture at two different states (plane strain tension and equibiaxial tension) agree well with the calibrated results of macromechanical modeling, illustrating the validity and predictive capability of the proposed approach. Furthermore, the approach is applied to a microstructure sensitivity study on artificial microstructure models with different microstructure constitutes to investigate the influence of microstructure on the behavior of cleavage fracture. Therefore, the new approach is contributing to the material design directly.