Research on several constitutive models to predict the flow behaviour of GCr15 continuous casting bloom with heavy reduction

In this work, the modified Johnson-Cook (J-C) model was developed. The predictive abilities of the JC model, new modified JC model, modified Zerilli-Armstrong (ZA) model, and strain-compensated Arrhenius model of the flow behaviour of GCr15 continuous casting bloom with heavy reduction (HR) were compared. The deformation mechanism was explored. Experimental stress-strain data from single-pass thermo-simulation compression experiments over a wide range of temperatures (1023-1573 K), strains (0.05-0.7) and strain rates (0.001-0.1 s(-1)) were applied to deduce the material parameters of these constitutive models. The applicability of the models was analysed by calculating the correlation coefficient; the average relative error (AARE) of the model; and the number of model parameters, which represents the computation time of each model. The experimental results showed that the new modified JC model was more suitable for describing the flow behaviour of GCr15 continuous casting bloom with HR because of its convenient calculation and better accuracy.