Influence of ageing temperature on dynamic fracture toughness of 10Ni3MnCuAl die steel

摘要

The dynamic fracture toughness K_(ld) of the precipitation hardening martensitic die steel 10Ni3MnCuAl was tested after ageing at different temperatures. The test results showed that the K_(ld) value is low at the peak hardness temperature and increased rapidly with the increase of ageing temperature. The SEM fractography changed from intergranular plus quasi-cleavage to dimple morphology. Analysis showed that dynamic fracture toughness K_(ld) is related to the number of precipitate which took part in the nucleation of microcracks in the plastic region of the crack tip.