Development of a Process Model for Online-Optimization of Open Die Forging of Large Workpieces

摘要

The basic idea of this paper is developing process models which are online capable, i.e. which combine data from online measurements and simplified plastomechanical interrelations for the forecast of equivalent strain, equivalent strain rate and the temperature in the core of the part being forged. These models deliver the numerical basis for the forecast of the microstructures obtained. In combination with optimization methods a numerical assistant for the forging press operator can be implemented. At the Institute of Metal Forming of the RWTH Aachen University, models for the core fibre of a forged block were developed. The development of the models was based on reference solutions which were derived from FEM-calculations. The equivalent strain and equivalent strain rate are thereby determined by the change of the geometry of the workpiece (i.e. change in length or change in height). For the determination of the temperature distribution along the core fibre an explicit Finite Difference model is used. This model considers the loss of temperature at the surface due to radiation and convection, and also the dissipation in the core fibre. For the subsequent prediction of the microstructure the module STRUCSIM, which was developed at the Institute of Metal Forming, is used. The results of the models show good agreements with the FEM-solutions.