Hot deformation behaviour and processing map of a typical Fe-Mn-Si-Cr steel for automotive body structures

摘要

The hot deformation behaviour and processing maps of a typical Fe-Mn-Si-Cr steel for automotive body structures were investigated on a Gleeble3500 simulation tester by isothermal compression test in the temperature ranging of 950 degrees C to 1150 degrees C and a strain rate of 0.05-10 s(-1). The results show that dynamic recrystallisation softening mechanism is more evident at low strain rate, while dynamic recovery is more evident at high strain rate. The instability parameter xi((epsilon) over dot) values are negative and considered as unsafe deformation zones at low deformation temperature and high strain rates. The processing maps exhibit two safe domains for hot working: (a) 0.05-1 s(-1) and 1080-1150 degrees C, the power dissipation values of eta increase with the increase of strain rate. (b) 0.05-1 s(-1) and 950-1020 degrees C, while strain is lower than 0.1, the values of eta decrease with the increase of strain rate.