Topic: Process and Materials Modelling in Incremental Forging and Ring Rolling

Speaker: Prof. Dr.-Ing. Gerhard Hirt

          Institute of Metal Forming (IBF), RWTH Aachen University, Germany

The lecture presents two selected topics in the field of modelling of incremental forming processes:

(1) For open die forging a simplified online model is presented to assist the press operator by displaying the current distributions of strain, temperature and grain size along the centerline of the workpiece.

(2) For FEM simulation of ring rolling the time dependent degrees of freedom for the tools movements are feedback controlled based on the developing ring geometry and the machines power limits. To achieve this  virtual sensors as well as adequate feedback control algorithms are included in the ring rolling simulation.

Process Modifications & Process Modelling for Rolling of Tailored Products

The majority of all metals will undergo a rolling process during the production chain from metal generation to the final product. These rolling processes define the product geometry, the material properties or functional surface properties. The lecture reviews selected processes for tailor rolled products as well as modeling techniques helping to design or optimize these processes. Their common goal is to improve material efficiency in flat rolling and in application of rolled products.

Tailoring the Product Properties of High Manganese Steels

Twin roll strip casting can be an effective alternative to produce high manganese TWIP steel, which provides extraordinary mechanical properties. In the work presented, 1.5-3 mm thin hot strips with up to 30 wt% manganese were produced directly from the melt and further processed to cold strip. An adapted thermo-mechanical treatment, consisting of cold rolling with or without subsequent annealing, enables to adjust different material states, such as recrystallised or strengthened state, and thus to tailor the mechanical properties. As an example for the superior crash behaviour of high manganese TWIP steels, dynamic crash tests were carried out using cold rolled Fe-29Mn-0.3C steel in different material states.