Structure and Mechanical Properties of High-Manganese Steels

This chapter presents results from investigations about high-manganese austenitic steels, which have gained increasing importance over the recent two decades. Intense research into this group of steels indicates the need for employing them in the global automotive sector, especially for constructional components of cars absorbing impact energy in road collisions. The examples of extensive research over this group of high-manganese austenitic steels have been pursued by the authors at the Division of Materials Processing Technology, Management and Computer Techniques in Materials Science, the Institute of Engineering Materials and Biomaterials of the Silesian University of Technology, Gliwice, Poland. The essence of the research concerns the designing of thermo-mechanical processing of selected high-manganese austenitic steels with carefully selected but diversified chemical composition in order to refine their structure and improve mechanical properties. Thermo-mechanical processing was performed using a thermo-mechanical simulator DSI (Dynamic System Inc.) Gleeble 3800. The results of the investigations performed with the DSI simulator allowed to design different variants of hot rolling consisting of several stages for the investigated high-manganese austenitic steels. Different processes controlling the curve of strain hardening could be used by applying the varied conditions of thermo-mechanical processing, and especially a diversified degree of deformation and isothermal heat treatment after finishing plastic working, such as dynamic recovery, dynamic recrystallization, and static recrystallization.