The metadynamic recrystallization in the two-stage isothermal compression of 300M steel

The two-stage isothermal compression are carried out at the deformation temperatures of 1173-1373 K, strain rates of 0.1-5.0 s−1, and a strain of 0.69 and the inter-pass times of 0.2-5.0 s after the first stage isothermal compression in order to investigate the metadynamic recrystallization of 300M steel. The experimental results show that the metadynamic softening fraction rapidly increases with the increasing of deformation temperature and strain rate. According to the present experimental results, the kinetic equation for the metadynamic recrystallization of 300M steel is proposed. The volume fraction in the metadynamic recrystallization Xm is presented as follows: Xm=1−exp[−0.693(t/t0.5)0.69], and the time for the metadynamic softening fraction of 50%, t0.5=9.7×10−7ε̇−0.27 exp[14103/(RT)]. The calculated results are in a good agreement with the experimental, which indicates that the present kinetic equation can be used to characterize the metadynamic recrystallization behavior in the isothermal compression of 300M steel.