Effect of grain and twin boundaries on the hardening mechanisms of twinning-induced plasticity steels

New experimental data related to the grain size and the Bauschinger effects have been obtained from a high-manganese austenitic twinning-induced plasticity steel. As the data show a strong contribution of kinematic hardening to the mechanical behaviour, a new physical-based model describing the isotropic and kinematic hardening is presented and validated in relation to the grain size and the twin spacing during straining.