Constitutive Modeling and Activation Energy Maps for a Continuously Cast Hyperperitectic Steel

An appropriate experimental scheme and an accurate constitutive model are the two key factors that determine the success or failure of the constitutive equations used to simulate hot deformation behavior during the continuous casting process. In this study, according to the characteristics of the thin-slab continuous casting process, the experimental scheme on hot tensile tests is designed and validated by the analysis of fracture surfaces. Isothermal hot tensile tests were performed on a Gleeble 1500 thermomechanical simulator at four different temperatures (1173 K, 1273 K, 1373 K, and 1473 K) and four different strain rates (10⁻³, 10⁻², 10⁻¹, and 1 s⁻¹). Based on the flow stress obtained from the tensile tests, the Arrhenius-type constitutive equation was established. It is shown that the simulation results are in good agreement with the experimental data. To further understand the constitutive behavior, activation energy maps were also developed in this study. Through a brief analysis of the activation energy map, directions for future work were surmised.