Conclusion

The heat treatment of tool steels has undergone considerable development over the past decade, particularly in terms of understanding secondary hardening mechanisms, furnace operation and the optimization of quenching conditions to minimize deformation and the risk of tapping. The use of finite element codes now makes it possible to predict, based on tool geometry, dangerous stress concentration zones where there is a risk of fracture during quenching. In addition, the monitoring of treatment atmospheres makes it possible to control directly the exchange of carbon from the metal to the outside, and consequently the risks of decarburization. With the increasing use of high-pressure gas quenching and rapid quenching kinetics for large-scale tooling, the quality of heat treatment in vacuum furnaces has improved considerably over the last decade. The result is a significant reduction in deformation...