Understanding thermal compression and deformation behavior of 3.15 wt.% Si non-oriented electrical steels prepared by sub-rapid solidification

Sub-rapid solidification has the potential to enhance the columnar structure and the magnetic property of electrical steels. However, research on the hot deformation behavior of sub-rapid solidified non-oriented electrical steel, particularly at varying strain rates, has yet to be fully understood. The effect of thermal compression on the microstructure and mechanical properties of 3.15 wt.% Si non-oriented electrical steel strips produced through a strip casting simulator was systematically investigated. The findings reveal that increasing the deformation temperature enhances grain recrystallization, while the peak stress decreases with higher temperature. Furthermore, a lower strain rate favors dynamic recrystallization and reduces thermal stress. It can be seen that sub-rapid solidification can effectively reduce the thermal activation energy of non-oriented electrical steel, and the thermal activation energy is calculated to be 204.411 kJ/mol. In addition, the kinetic models for the dynamic recrystallization volume fraction of the studied 3.15 wt.% Si non-oriented electrical steel were established.