Mikrostrukturbasierte Prozesskettenmodelle zur Produkt- und Prozessoptimierung in der Kaltmassivumformung [thesis]

Konstantin Schacht, Wolfgang Peter Bleck, Ulrich Prahl
2018
In this thesis, a microstructural / dislocation-density-based through-process material model is developed for simulation of metal forming processes and subsequent product and process optimization. After the calibration of the material model through single hit uniaxial compression tests, the model can predict the flow stress for different materials belonging to one alloy family with one set of parameters. The microstructural material model is can be applied to various deformation tests and
more » ... rial cold bulk forming processes. Application of this constitutive model in metal forming simulations gives insight to the microstructure evolution during the production process. Considering the scientific questions formulated in chapter 3 the following conclusion can be drawn from this work:- The dislocation density and other parameters associated with the model are calculated at discretized times in the cold bulk forming process, including interpass time. Consequently, the developed model is naturally capable of continuous thermo-mechanical through process simulation.- The through-process model considers explicitly the chemical composition and is therefore capable of describing the flow behavior of case carburizing steels belonging MnCr alloy family depending on the chemical composition and microstructural state. All accessible quantities in the FEM simulation are calculated based on the chemical composition and the boundary condition of the production process (billet temperature, tool temperature etc.). Accordingly, for instance, the computation of the contact pressure is possible more accurately, which is the main reason for tool wear. Thus, since the average product cost is considerably influenced by the tool wear, a more precise calculation of the average product cost is realized. Hence, the through-process model is a good tool for the product and process optimization.- The microstructural / dislocation-density-based through-process material models are advantageous particularly with regard to their applicability to t [...]
doi:10.18154/rwth-2018-227131 fatcat:xa6bvt4ntng4pprcqhc2eftfse