Press hardening of manganese-boron steels has become a very popular process to produce ultra-high-strength steels for autobody components. However, the residual formability of these sheet components is greatly limited by the formation of fully martensitic microstructure during in-die quenching, which makes them only to a limited extent suitable for crash-relevant anti-intrusion parts. In order to extend the application range of press-hardened components, the use of third-generation advanced high strength steels (AHSS), i.e., medium-manganese steels, attracts increasing attention.
Aim of the presented research is to analyze the potential of press hardening of  lean medium manganese steel in combination with a quenching & partitioning (Q&P) treatment in comparison to intercritical annealing. For this reason, dilatometer investigations on Fe-0.3%C-5%Mn-1.5%Si with varying Q&P parameter were performed. By adjusting the heat treatment parameters, the microstructure and hence the mechanical properties were modified to fit the application´s load requirements. The results demonstrated that the performed Q&P treatments lead to multi-phase microstructures, consisting of martensite (tempered and fresh) and retained austenite resulting in high tensile strength, comparable to martensitic 22MnB5, and significantly improved total elongation up to 18 %. It was shown that a reasonable ductility requires not only the adjustment of the retained austenite content bit also a reduction of fresh martensite to prevent brittle failure. Finally, selected heat treatments were successfully transferred to a laboratory-scale press hardening system equipped with a heatable hat-shaped pressing tool.