Grain size effect on strain hardening in twinning-induced plasticity steels

We investigate the influence of grain size on the strain hardening of two Fe-22Mn-0.6C (wt.%) twinning-induced plasticity steels with average grain sizes of 3 and 50 mu m, respectively. The grain size has a significant influence on the strain hardening through the underlying microstructure. The dislocation substructure formed in the early deformation stages determines the density of nucleation sites for twins per unit grain boundary area which controls the developing twin substructure. (C) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.