The Effect of Thermo-Mechanical Treatment and Adding Niobium and Titanium on Microstructure and Mechanical Properties of TWIP Steel

Abstract

The effect of addition of Nb and Ti also cold rolling and annealing treatment on mechanical properties and microstructure of a twinning induced plasticity (TWIP) steel have been investigated. The results indicated that addition of Nb and Ti enhances strength. Also it is considered in the case that deformation twinning is suppressed, low stacking fault energy and Nb and Ti precipitation causes high elongation. It is because of limiteted dynamic recovery. In addition, increasing cold rolling reduction has been increased strength. The ductility increased with increasing annealing temperature; however, strength reduced. In centric limit of partial recrystallization regime, maximum increasing in work hardening capacity and also almost high yield strength has been achieved. Therefore, utilization of large cold rolling reduction and subsequently annealing treatment in the centric limit of partial recrystallization region was suggested as an effective method to obtain TWIP steel with an excellent combination of strength and ductility.