Temperature Influence on Section Uniformity of Casting Steel Rolled with the Hot-Core Heavy Reduction Rolling Process and Traditional Hot Rolling Process

Hot-core heavy reduction rolling (HHR2) is an innovative technology that uses a temperature gradient to improve the core quality of continuously cast steel at the end of solidification. In the current study, the influence of the temperature on the quality of continuously cast steel rolled with HHR2 is investigated through experiments and simulation. Four HHR2 processes with different surface deformation temperatures (800, 850, 950, and 1100 °C) are carried out. The results show that the surface deformation temperature of 1100 °C led to the best density quality of the steel compared with several other processes. Moreover, based on the cross-section temperature field and the influence of temperature on deformation resistance, an effective strain evaluation method of the billet center is proposed to analyze HHR2 billet deformed quality. Furthermore, the HHR2 processes and traditional hot rolling process are compared. The results show that the 1100 °C HHR2 process has a higher temperature gradient than traditional hot rolling with the same surface temperature, which enhances both the stress triaxiality ratio and effective strain to obtain a higher core quality billet.