Development of Hot-Work Tool Steel for High-Temperature Applications (UHB QRO80)

摘要

Five different martensitic hot-work tool steel alloys, two new alloys and three already established ones, have been investigated and compared with respect to decisive material properties. It is thereby demonstrated that a new alloy composition of type 0.4% C - 2.5% Cr - 2% Mo - 1.2% V (QRO 80) can offer significantly improved material properties, such as enhanced temper resistance and hot yield strength etc, in combination with moderate alloy element costs, thus constituting a good example of an alloy optimization for these purposes. Detailed examinations of microstructures have been made by transmission electron microscopy, and differences in mechanical properties between the alloys are discussed with reference to substructural features, such as temper carbides.