Fractography analysis and constitutive modeling for dynamic plasticity of austenite stainless steel (ASS 304) at hot-working temperatures

Abstract In industrial forming process a consistent and precise prediction of flow behavior of metals is vital in understanding the workability of the metal and enhancing parameters for hot forming process considering the coupled effects of strain, strain rate, and temperature. In this chapter, the tensile fracture behavior of the austenite stainless steel (ASS 304) alloy in three rolling directions is observed with scanning electron microscope (SEM) with respect to a range of magnifications. SEM examination revealed that microvoids and shallow dimples are observed at the fracture surface, indicating that the fracture is predominately ductile in nature and predicted mechanical properties of the material. Also, an examination on flow behavior of ASS 304 alloy is done using constitutive models. Five constitutive models, namely, modified Johnson–Cook (m-JC), modified Arrhenius-type equations (m-Arr), modified Zerilli–Armstrong (m-ZA), modified Fields–Backofen (m-FB), and Khan–Huang–Liang (KHL) models are developed to predict the flow stress. The forecasts of these constitutive models are compared with each other using arithmetic measures like correlation coefficient, average absolute error, and its standard deviation. Comparison of models with the three statistical measures, m-Arr model is a better model for predicting the flow stress, but considering the fact that physical models with more material constants predicts better flow behavior, m-ZA model is a physical based model; m-ZA model is preferred over the m-Arr model.