Isothermal and Thermal Fatigue of Martensitic Chromium Hot-Work Tool Steels

Abstract: A lot of our everyday products, e.g. car-parts and mobile phone covers, are shaped by using high temperature techniques, such as die casting, extrusion, forging or rolling. The die in all these forming processes play an important role, since it usually gives the object its final shape. The service-time of a die is essential, because the die is usually very complex and expensive. If the service-time could be increased then the production costs would be lowered.



The present study aims at increasing the service-time of hot work tool steels, by increasing the knowledge in dominant damage mechanisms and important material properties.



The cyclic behaviour and damage in martensitic chromium hot work tool steels, at four different heat treatment conditions, were investigated by isothermal and thermal fatigue testing. A kinematic and isotropic hardening model was used to model the material behaviour.