On the stress state dependence of the twinning rate and work hardening in twinning-induced plasticity steels

The influence of the stress state on the twinning rate and work hardening is studied in the case of an Fe-Mn-C TWIP steel strained in uniaxial tension, simple shear and rolling. The resulting stress-strain responses exhibit marked differences. The twinning rate, number of activated twinning systems in each grain, twin thickness and transmission of twins across grain boundaries are dependent on the imposed stress state during straining. Relationships between twin features and macroscopic work hardening rate are established. (C) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.