Effect of high temperature and high strain rate on the dynamic mechanical properties of Fe-30Mn-3Si-4Al TWIP steel

The dynamic mechanical properties of Fe-30Mn-3Si-4Al twinning induced plasticity (TWIP) steel were studied by the split-Hopkinson pressure bar (SHPB) at temperatures of 298-1073 K and strain rates of 700, 2500, and 5000 s(-1). The TWIP steel indicates strain rate hardening effect between 700 and 2500 s(-1), but it shows strain rate softening effect between 2500 and 5000 s(-1). In addition, the strain rate softening effect enhances with an increase in deformation temperature. After deformation, the microstructures were studied by optical microscopy (OM). It is shown that the deformation bands become more convergence, a part of which become interwoven with an increase in strain rate, and the dynamic recovery and recrystallization are enhanced with an increase in both temperature and strain rate.