Hot deformation behavior and softening mechanism of Fe-6.5Â 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.