Anwendung von Methoden der Bruchmechanik zur Lebensdauerverbesserung von Umformwerkzeugen

Application of Fracture Mechanics for the Improvement of the Life Time of Forming Dies An investigation was undertaken to determine the life times of dies when these life times are determined by crack propagation from such stress raisers as notches. Notched DCB specimens were used to investigate the processes of crack initiation and propagation in the high temperature steel X 40 CrMo V 51 at 500°C. The results showed that the life times depend both on the heat treatment of the material and also on the length of hold time at temperature. Hold times during the forming process should be minimized in order to avoid fast creep crack propagation.