An investigation into the room temperature mechanical properties and microstructural evolution of thermomechanically processed TWIP steel

The present work aims to positively impact the utilization of high-Mn TWIP steels through gaining a fundamental understanding of their microstructural evolution during high temperature rolling procedure. Towards this end, full annealed TWIP steel was thermomechanically processed (TMP) through hot rolling the work-pieces at 800, 950, and 1100 °C by the reductions of 30 and 60%. The restoration processes (i.e., recovery and recrystallization) are found to be operative during hot rolling of the examined steel. The discontinuous and geometrical dynamic recrystallization mechanisms are considered to contribute generating the fine-equiaxed microstructures. In addition, the distorted annealing twins hold a great contribution to the formation of new recrystallized grains. The room temperature mechanical properties of the hot rolled products were examined by tensile testing method. The results show that a significant strengthening would be achieved by applying the predetermined TMP cycles without a dramatic decrement in elongation to fracture. The changes in the yield and ultimate strength as well as the ductility values have been properly addressed considering the corresponding microstructural evolutions and texture effects.