Metadynamic Recrystallization in the Isothermal Double Compression of CP800 Steel

The production of automotive steel sheets achieved by the compact steel production (CSP) process has become an ongoing research topic in industry due to the global demand for decarbonization. Identifying the hot deformation behaviors, especially the metadynamic softening mechanism between passes is critical to drawing the picture of processability under the character of the CSP process. In this study, the metadynamic softening behavior of CP800 steel which is prepared for the application CSP process was investigated through the isothermal double compression tests which were carried out at the deformation temperatures of 1173, 1273, and 1373 K, and strain rates of 0.1,1, and 5.0 s−1, and the interpass times of 1, 10, and 20 s. The softening behavior was discussed through the deformation flow stress-strain curves under different conditions. The kinetic equation of metadynamic recrystallization is proposed and examined with experimental results. The effect of 42 μm and 92 μm two different sizes of initial austenite grains on metadynamic recrystallization were analyzed. The obtained findings of this study are highly recommended for the design and optimization of the application of the CSP process when producing CP800 steel.