Developments in Die Casting Die Steels.

Type X 2 NiCoMo 18 8 5 (VEW-W721), X 2 NiCoMo 18 9 5 (VEW-W720), and X 2 NiCoMoTi 18 12 4 (VEW-W725) maraging steels for diecsting dies are hardened by aging at 480 degree C for 3 hr. They have a very good dimensional accuracy and their surface is practically free of oxidation. In addition to unproblematic hardening, these steels feature the following properties: a good ductility, weldability, hobbability, and thermal shock resistivity. These properties make these steels ideally applicable for both cold and hot working tools in contrast to conventional steels. Examples are presented which illustrate that the higher price of these high-alloy steels can be offset by a longer service life and lower machining costs.