Dynamic recrystallization in a 304 stainless steel : microtexture measurements and models

Orientation imaging microscopy (OIM) was performed on hot twisted polycrystalline 304 stainless steel specimens in order to study the characteristics of dynamic recrystallization (DRX) in low stacking fault energy FCC metals. Microtexture analyses were carried out and the misorientation statistics of the recrystallized areas were derived. The results revealed that multiple twinning controls the formation of new orientations. DRX macrotextures were also measured in torsion and compression. These textures are highly sensitive to the deformation (Zener-Hollomon) parameter Z. High Z values lead to overall textures controlled by nucleation, whereas, at low Z values, selective growth is more predominant.A deformation and recrystallization model based on the OIM measurements and the steady state properties is proposed. The observed strong brass-type deformation textures were simulated by introducing self hardening coefficients. The transition from single to multiple-peak flow during DRX was investigated, together with the evolution of the grain size distribution. In particular, the effect of twinning on the evolution of the latter was simulated. Finally, it is shown that the model simulates texture development during DRX very well