Advanced microstructure modeling for hot forming processes with transient forming conditions based on multi-scale microstructure simulation

• Applicant: Professor Dr.-Ing. Gerhard Hirt
• Subject Area: Primary Shaping and Reshaping Technology, Additive Manufacturing
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 525187623

Within the scope of the proposed project, a semi-empirical microstructure model for hot forming will be extended to cover also microstructure effects caused by transient forming conditions. This new model will be able to include the delayed reaction of the microstructure to rapidly changing forming conditions when coupled with an FE simulation, and thus, achieve a more precise digital twin of the microstructure state along the forming process. For this purpose, a dependence of the delay on different process boundary condition changes shall first be derived based on experimental characterization tests and physically based full-field simulations. The general applicability of the simulative characterization of the microstructure reaction with the aid of full-field simulations has already been demonstrated by own preliminary work. The next step is to apply these simulations specifically to transient boundary conditions of a hot rolling process using an exemplary case-hardened steel, to quantify the relation of transient boundary conditions and microstructural changes, and to summarize it in a semi-empirical description. In doing so, the project aims to clarify which microstructural mechanisms are particularly affected and are leading to the delayed material response. Finally, this new approach will be implemented as an example in the semi-empirical microstructure model StrucSim, which is available at the Institute of Metal Forming, and a validation of the extended StrucSim version based on an experimental hot rolling process will be performed.

• DFG Programme: Research Grants