LAUSR

The present study deals with the deformation behaviour of low carbon and high manganese twinning-induced plasticity (TWIP) steel (Fe–21Mn–3Si–3Al–0.06C, wt%) through microstructural investigation. Low carbon with high manganese along with the addition of aluminium in TWIP steel results in lowering of specific weight with higher strain hardening due to the formation of mechanical twins during deformation. The full austenite phase is obtained after solution treatment and deformation twins appear and austenite grains become flattened during application of 10% to 50% cold deformation. The annealing twins are relatively coarser compared to the newly formed deformation twins. With the increasing amount of cold deformation, deformation twins and dislocation density are increased. Deformation twinning can be considered to be the dominant deformation mechanism during the course of cold rolling applied in the present study. The cold deformation results in the evolution of dislocation substructure, stacking faults, deformation twins and twin–dislocation interaction, which may be correlated with the lower stacking fault energy (∼24 mJ/m2) of the investigated steel. Excellent combination of strength and ductility has been obtained in the present TWIP steel with a small rolling reduction of 10% and 30%. With the increasing amount of cold deformation, tensile strength notably increases and maximum tensile strength is obtained at 50% cold-deformed sample along with the diminutive sacrifice of the ductility.