Sprühkompaktierte hochlegierte Werkzeugstähle - Herstellung und Eigenschaften

Especially for high-alloyed tool steels users requirements on properties need compromises in alloy composition and formation of phases. As an example high ductility requires small carbides while large carbides enhance abrasive wear resistance. Until now only powder metallurgy (PM) was the only tool to produce complex alloys with high amounts of hard phases. In the last years spray forming has been developed. The new production route gives a compromise of casting and PM: gas atomization and rapid solidification of the melt on one side, direct forming without a mould on the other. By this technique a short production route is offered. In addition the process leads to an intermediate state of the primary structure; resulting in modified post-processing and variations in properties. The paper presents microstructure, homogeneity of composition, as well as wear properties and fracture behavior of spray formed high-alloyed steels (e.g. X153XrMoV12, X290Cr12, HS6-5-2C) and intercomparison with conventionally produced material as well as PM material. It is shown that spray formed high alloyed tool steels are superior to conventional route in all cases. Focusing on the relation between toughness and wear resistance PM steels still seem to show some advantages, but the SF steels offer a combination of properties that justify their discreteness.