Comparison of phenomenological and physical-based constitutive material models for Cr17Mn17Mo3NiN low nickel stainless steel

Phenomenological and physical-based constitutive models for the Cr17Mn17Mo3NiN low nickel stainless steel were developed based on the true stress-strain curves acquired from isothermal uniaxial compression tests. The compression tests were performed at various deformation conditions (strain rate 0.01, 0.1, 1, 10 s-1, temperature 950, 1000, 1050, 1100 ºC). For higher prediction accuracy, the modified Johnson–Cook model was improved by using the Nelder function, while the microstructural-based constitutive model was phenomenologically modified. Then, the prediction accuracy of the proposed constitutive models was estimated and compared. As a result, the flow stresses predicted by the newly modified Johnson-Cook model and the microstructural-based constitutive model were in good consistent with the experimental results. Especially, the prediction accuracy of the microstructural-based constitutive model was the highest. The average absolute relative error, the determination coefficient, the mean absolute error and the root mean square error of it were 1.07%, 0.9979, 1.7MPa and 2.5MPa, respectively. In consequence of all, it was come to the conclusion that the proposed microstructural-based constitutive model is wonderfully suitable to the simulation and optimization of hot working processes of Cr17Mn17Mo3NiN low nickel austenitic stainless steel.