Flow behaviour constitutive model of CuCrZr alloy and 35CrMo steel based on dynamic recrystallization softening effect under elevated temperature

In order to study the effect of dynamic recrystallization on the metal flow behavior during thermal deformation, the elevated temperature compression experiments of CuCrZr alloy and 35CrMo steel are carried out using Gleeble-3810 thermal simulator. It is proved that the samples underwent obvious dynamic recrystallization behavior during thermal deformation by microstructure observation of deformed specimens. The size of recrystallized grains increases as the temperature improved and the strain rate decreased. Meanwhile, the net softening rate caused by dynamic recrystallization is determined based on the stress-dislocation relationship. It can be found that the value of net softening rate increases quadratically as the Z parameter decreases, and the dynamic recrystallization net softening rate of CuCrZr alloy and 35CrMo steel are calculated to be 21.9% and 29.8%, respectively. Based on the dynamic recrystallization softening effect proposed, the novel elevated temperature flow constitutive models of two different alloys are proposed, and the related parameters are well defined and solved in detail. The predicted values of the obtained models are agreed well with the experimental values.