Austempering effect on structure properties and performances of hot-work tool steel

In this article an investigation has been carried out on different austempering cycles conducted on samples of the most diffused hot-work tool steel: AISI H 11. The laboratory tests have been addressed to the examination of the structure and to the evaluation of its mechanical properties: the hardness, the impact strength and the thermal fatigue. The aim of the analysis is to verify what are the effects of structure transformation, of different austempering temperature and of the microstructure morphology on the mechanical properties in terms of impact-absorbed energy and thermal fatigue resistance. The ultimate application aimed at for such heat treatment study is the high-pressure die casting and the enhancement of the performance of the relative tools.