Model establishment for flow stress of 41Cr4 steel in hot working

For obtaining the volume fraction of dynamic recrystallization, true-stress, true-strain, peak-stress, peak-strain of 41Cr4 steel in the hot working, a physical simulation test was performed by GLEEBLE 3500 subject under conditions of different temperatures, strain and strain rates. The result indicates that in the beginning of deformation, the dislocation density increases quickly, so the flow-stress increases quickly. Therefore, the phenomenon of work hardening occurs. With the cumulation of strain, the increasing velocity of flow-stress becomes slow little by little. When the strain rises to exceed the critical strain, the flow-stress decreases for the dynamic recrystallization softening. Based on this physical simulation test, a novel model for flow stress of 41Cr4 steel is established with consideration of the influence of work hardening, dynamic recovery and dynamic recrystallization on the flow stress. Compared with the experimental data, it is proved that the model established is effective and can be used in practice.