Title: Properties of double dispersed tool steels

Authors: T. Schneiders, W. Theisen

Addresses: Schmolz + Bickenbach Guss GmbH & Co. KG, Hulser Str. 810, D-47803 Krefeld, Germany. ' Materials Technology, Ruhr Universitat Bochum, Lehrstuhl Werkstofftechnik, D-44780 Bochum, Germany

Abstract: The aim of this study was to develop a new tool material, which combines the toughness of Hot-Work Steel (HWS) with the wear resistance of High-Speed Steel (HSS). This has been realised via powder metallurgy by blending HWS and HSS powders. The blend, which may contain up to 30 vol.% of high-speed steel powders (grain size 150 microns), is subjected to Hot Isostatic Pressing (HIP). This results in a microstructure that shows a double dispersion of coarse HSS clusters with dispersed small carbides (< 5 microns) in a martensitic HWS matrix without carbides. The new materials can be treated to produce hardness levels of between 40 and 60 HRC. The materials were examined with respect to their wear resistance and fracture toughness and the results obtained were correlated to the microstructure. It is shown that the wear rate of the double dispersed material decreases as the HSS content increases without causing a significant reduction in fracture toughness.

Keywords: hot-work steel; HWS; high speed steels; HSS; powder metallurgy; double dispersion; wear resistance; fracture toughness; tool steels; hot isostatic pressing; HIP; microstructure.

DOI: 10.1504/IJMMP.2008.018728

International Journal of Microstructure and Materials Properties, 2008 Vol.3 No.2/3, pp.206 - 215

Published online: 16 Jun 2008 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article