BEHAVIOR AND MECHANISM OF HOT WORK-HARDENING FOR 316L STAINLESS STEEL

The characteristics of hot work-hardening for 316L stainless steel have been systematically studied through high temperature compression tests on the Gleeble-1500 thermal simulation testing machine. According to Ludwik true stress-strain model, the experimental data has been regressed by using nonlinear Fitting method, and the n value in Ludwik model, a comprehensive index which reflects the competitive result between work-hardening and softening, has been calculated with Crussard-Jaoul method. The dynamic recrystallization and twinning were observed by OM and TEM. The experiments reveal that 316L stainless steel is easy to work-hardening during hot deformation, and deformation rate can effect n(C-J)-epsilon curves and variation law, There is no peak stress on its true stress-strain curves, but partial dynamic recrystallization has occurred during hot working process. This incomplete softening mechanism can't counteract the effect of hot work-hardening, so the true stress-strain curves still rise with deformation increasing; In addition, twinning occurred during hot working is one of the major mechanisms of hot work-hardening.