Approaches to materials and manufacturing technology for effective machining of high-strength austenitic CrMn steels

• Applicants: Professor Dr.-Ing. Dirk Biermann; Professor Dr.-Ing. Sebastian Weber
• Subject Area: Metal-Cutting and Abrasive Manufacturing Engineering
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 534062323

Austenitic chromium-manganese steels with a high content of interstitially bonded carbon and nitrogen, also known as high-interstitial steels (HIS), are characterized by their wide-ranging properties as high-performance materials: On the one hand, they have high strength in the solution-annealed state, which means they can be used as wear-resistant structural materials for mechanically loaded components. Components made from HIS can be used effectively in acidic environments due to the increased chromium content, which makes them highly resistant to various types of corrosion. On the other hand, in the solution-annealed condition they have paramagnetic properties, which are required, for example, for housings in measurement technology due to their permeability to electromagnetic waves. Compared with the widely applied austenitic materials, the CrMn steels under consideration remain paramagnetic even under large plastic deformations. Very high austenite stability is achieved without the addition of alloying elements such as high-priced nickel, which has a limited global availability. This, on the other hand, contributes to manufacturing challenges in the mechanical processing of HIS that are not sufficiently solved. In the solution-annealed condition, which is suitable for the specific applications, only comparatively low feed rates can be implemented due to the extreme hardening capacity, which at the same time leads to intensive wear effects. In the context of the initial situation described above, this research project presents approaches that plausibly lead to a significant improvement in the machinability of HIS. Both materials engineering approaches to an adapted heat treatment strategy and the production engineering consideration of the resulting fundamentally changed machinability are explained within the scope of the research project.

• DFG Programme: Research Grants