Hot deformation behavior and softening mechanism of Fe–6.5 wt% Si alloy

Hot deformation behavior of Fe–6.5 wt% Si alloy is studied by hot compression in the temperature range of 773–1373 K with different strain rates. It is found that dynamic recrystallization is the main softening mechanism in disordered phase regions in 1073–1373 K, while dynamic recovery is the main softening mechanism in ordered phase regions in 773–973 K. The strain rate sensitivity increases with temperature in 773–973 K, while decreases in 1073–1373 K. The apparent activation energy is calculated to be 211 kJ/mol in 1073–1373 K and 478 kJ/mol in 773–973 K. The function between steady flow stress and Zener–Hollomon parameter is deduced. Moreover, the relationship between steady flow stress and the grain size after deformation is presented the Hall–Petch relation.