Influence of Strain Rate on the Activation of {110}, {112}, {123} Slip in Ferrite of a Dual Phase Steel

We have performed micro pillar compression to investigate the influence of strain rate on the activation of three slip plane families, namely {110}, {112} and {123}, in ferrite of a dual phase steel (DP800). The critical resolved shear stress of all slip plane families rises with an increased strain rate. The strain rate sensitivity drops with increasing strain. The increasing strain rate does not reduce the number of activated slip systems, however, results in a successive breakdown of Schmid's law. The activation volume of 13b³-16b³ suggest that the Peierl's process is the rate controlling mechanism in ferrite of DP800.