Hot Deformation Behavior of Stainless Steel Containing Boron

The stainless steel containing boron was prepared by vacuum induction melting technique with adding 1.96wt% boron into 304 stainless steel. The hot deformation behavior of the steel was investigated by single pass hot compression tests at 900-1 150 ℃ and strain rate of 0.1-10 s^-1. The hot deformation constitutive model of the steel was established by Arrhenius equation with five degree polynomial fitting combined with test data. The critical condition of dynamic recrystallization of the steel was determined by analysis of the work-hardening rate-true stress curves. The results show that the flow stress-strain curves of stainless steel containing boron presented a typical dynamic recrystallization type, and the dominated softening mechanism was dynamic recrystallization after hot compression under the test parameters. With increasing deformation temperature or decreasing strain rate, the peak stress and its corresponding true strain of the test steel decreased. The true stress-true strain curves calculated by the established hot deformation constitutive equation had a good agreement with the test results, and the average absolute relative error was 2.76%, indicating that the constitutive model could precisely predict the hot deformation behavior of stainless steel containing boron. The dynamic recrystallization of the steel occurred easily when the deformation temperature was relatively high and strain rate was relatively small.