Supersolidus Sintering and Mechanical Properties of Water Atomized Fe–2·3C–4·0Cr–7·0Mo–10·5Co–6·5V–6·5W High Speed Steel

ASP60 high speed steel is produced from gas atomised powder, subsequently encapsulated and hot isostatically pressed below the solidus temperature, the billets being further rolled as bars or rods. The microstructures of this material show a very fine carbide distribution which results in high values of fracture strength and wear resistance. This paper presents results of a study of the processing of steel of the same composition by an alternative PM route, using water atomised powder, die compacted and vacuum sintered, in order to obtain near net shapes. The density achieved by supersolidus liquid phase sintering at ∼ 1240° C was ∼ 99.9 % of the theoretical, but the carbides were coarser, ∼ 20 μm, compared with < 4 μm for ASP60