Large-Scale Void Closure Behavior during Hot Rolling: Experiment and Numerical Simulation

In this research, to clarify the void closure behavior of large-scale voids elongated in the normal direction, artificial void was introduced to steel plate and hot rolling experiments were conducted at 1000 °C. The void height was systematically changed to investigate the influence on the closure behavior. The closure process was compared with a predicting criteria called Q value. The results show that the closure behavior varies significantly with the increasing of height, the dominant closing direction shifts from the normal direction to the transverse direction, and the critical Q value criteria was not appliable for all cases. To discuss the applicability of the Q value, a representative volume element was built, and finite element analysis under systematically controlled stress state was conducted. The Q value criterion under different stress states has been established.