Combined deformation twinning and short-range ordering causes serrated flow in high-manganese steels

Abstract

The isolated impact of deformation twinning and short-range ordering on the serrated flow phenomena in two high-manganese twinning-induced plasticity steels, an X60Mn18 and an X30MnAl17-1 alloy, was studied via quasistatic tensile tests at room temperature and at 150 °C. In order to identify the effect of prior deformation twins, both alloys were investigated in recrystallized and non-recrystallized states. The experimental data suggest that the inhibition of the movement of trailing partial dislocations by short-range ordered clusters results in a promotion of deformation twinning. A multi-scale model is introduced to connect short-range ordering theory, deformation twinning, the formation and propagation of deformation bands and the occurrence of serrated flow.