Flow stress and constitutive relations of ship plate steel continuous casting slab with solidification end reduction process

In order to describe the thermal–mechanical behavior of the ship plate steel continuous casting slab during solidification end heavy reduction (HR) process accurately, its constitutive behavior was investigated by a single-pass thermal compression experiment. According to the deformation features of wide thick continuous casting slab with HR, the simulation temperature ranged from 1173 to 1573 K with strain rates of 0.0001, 0.001, 0.01 and 0.1 s−1. Three different constitutive models, the modified Johnson–Cook (JC) model, the modified Zerilli–Armstrong (ZA) model and the Arrhenius model, were established according to the obtained true stress–strain curves. The average relative error of the modified JC model, the modified ZA model and the Arrhenius model are 10.82%, 9.96% and 6.21%, respectively. Considering the obvious softening effect of the flow curve at a low strain rate, the secondary softening factor under the interaction of low strain rate and the temperature was introduced in the original Arrhenius model. Compared to the Arrhenius model, the modified Arrhenius model error decreased from 6.21% to 4.73%.