Thermo-mechanical treatment of Fe–Mn–(Al, Si) TRIP/TWIP steels

Recent development in group of Fe–Mn–Al–Si steels with high-manganese content demands for more research in thermo-mechanical treatment and development of microstructure in such steels. Hot working conditions on forming the structure and course of the heat activated processes, removing the strain hardening effects, have been investigated. The chemical compositions of two high-manganese austenitic TRIP/TWIP steels containing various Mn concentrations were developed. Additionally, the steels were microalloyed by Nb and Ti in order to control the grain growth under hot-working conditions. The force-energetic parameters of hot-working were determined in continuous and multi-stage compression test performed in temperature range from 850 to 1100 °C and strain rate of 0.1, 1, 10 s−1 using the Gleeble 3800 thermo-mechanical simulator. The microstructure of investigated steels was determined in metallographic investigations using light microscope as well as X-ray diffraction. It was found that the thermo-mechanical treatment conditions have no influence on phase composition of the investigated steels.