Effect of Annealing on Microstructure and Mechanical Behaviour of Cold Rolled Low C, High Mn TWIP Steel

摘要

In the present study, 10% and 30% cold rolled Fe-21 Mn-3 Si-3 A1-0.06C TWIP steels have been annealed in the temperature range of 600-900°C for a short duration of 5 min. Optical and TEM microstructures reveal dislocations, micro-shear bands, deformation twins as well as interaction of dislocations and twins when deformed 10-30% by cold rolling. After annealing in the temperature range of 600-800°C, cold deformed austenite structures undergo recovery, whereas recystallisation occurs at 900°C. It is noticed that the hardness, yield strength and tensile strength of the specimens increase whereas percentage elongation decreases as the amount of cold rolling reduction increases. Tensile test results show improvement in ductility and decrease in tensile strength of cold rolled samples subjected to annealing at 600°C. 30% cold rolling and annealing can be considered as an effective method to obtain submicron grain with an attractive combination of strength and ductility.