Strain hardening behavior of TWIP steel in plastic deformation with temperature

摘要

Considering dynamic recovery/recrystallization and twinning effects, in this paper we develop a dislocation-based model to study the strain hardening behavior of TWIP steel. In the model, the dislocation evolution is controlled through a dynamic recovery/recrystallization process at high temperatures, and is primarily dominated by a twinning-induced plasticity (TWIP) process at moderate/ambient temperatures. The corresponding dislocation evolution model is established based on irreversible thermodynamics at high temperatures and conventional plasticity theory at moderate/ambient temperatures, respectively. A factor of delta is introduced to reflect the mixture effect of dynamic recovery/recrystallization and twinning on dislocation evolution, and d increases with deformation temperature. The stress-strain response and strain hardening behavior of TWIP steel (Fe-22Mn-0.6C) are validated at 293, 473, 573, 673, 773 and 873 K. Moreover, the mixture influence of dynamic recovery/recrystallization and twinning on the strain hardening behavior of TWIP steel is analyzed at 293, 473 and 573 K.