NUMERICAL ANALYSIS OF THE VOID EVOLUTION DURING METAL PLASTIC DEFORMATION

摘要

Quality of the die forgings essentially depends on the material defects (voids) and possibilities of their correction during the forging process. Material defects cause unfavourable plastic strain distribution in the forging volume. In case of precise forging the defects also have impact on the precision of forging geometry. In the paper a numerical simulation of the material void influence on the die forging process has been presented. Two first operations of the die forging process, i.e. upsetting and preparing have been analysed. Numerical calculations have been made with the ADINA System based on the Finite Element Method. Elastic properties of the dies made from hot-work tool steel and elastic-plastic properties of the deformed material (LH15 bearing steel) have been assumed in the numerical model. For the sake of axial symmetry the model has been simplified. On the basis of numerical simulation analysis the possible way of solving some problems occurring during design of die forging process will be presented.