Effect of hot forging and Mn content on austenitic stainless steel containing high carbon

This paper is a trial to process austenitic stainless steel of different manganese contents 4.35, 6.48 and 9.27 wt%. The high temperature deformation was in range less than 1200 down to 950 °C to prevent the hot severe cracks. The tensile strength increase as the Mn contents increases before and after thermomechanical treatment. For 4.35 and 6.48 Mn steels, the high deformation temperature accelerates the dynamic recrystallization of Fe–Mn steels leading to fine grains. The ferrite phase increases as the Mn contents increases. Sigma phase after thermomechanical deformation miniaturizes and the final microstructure is fully austenitic surrounded by thin carbides on the grain boundaries. For 9 wt%Mn steel, partial dynamic recrystallization happens and this deteriorates the strength and ductility.

► This paper is discussing the effect of Mn on the microstructure in existence of high carbon content.
► The high deformation temperature accelerates the dynamic recrystallization of Fe–Mn steels resulting in fine grains.
► Increasing Mn content than 7 wt% in austenitic stainless steel generally decreases the dynamic recrystallization effect on the grain size.