Characterisation and modelling of the flow behaviour of a medium manganese steel for hot forming

Medium manganese steels offer a wide range of advantages in hot forming compared to conventional boron steels such as lower heating temperatures and critical quenching rates. Furthermore, the combination of increased strength and ductility makes them a promising material for lightweight components in the mobility sector. For an efficient process design of such components, the finite element simulation is an effective tool to identify a suitable process window and minimise experimental trial-and-error tests. However, a realistic modelling of the material behaviour is essential for reliable simulation results. Therefore, this research focuses on the characterisation and modelling of the flow behaviour of a novel medium manganese steel for the simulation of hot forming processes. Isothermal tensile tests are carried out in a forming and quenching dilatometer under varying forming temperatures and strain rates. To reproduce the heat treatment at the steel producer and the hot forming at the parts manufacturer, the specimens are heat-treated before forming in a process route consisting of annealing, cooling and reheating. After the tests, flow curves are evaluated and modelled using different hardening laws, which are verified by means of numerical simulations.