High-Speed Tool Steels by Particle Metallurgy

Application of the powder or particle metallurgical (P/M) method to the production of high-speed tool steels is an effective means of controlling segregation problems. Macro- and microsegregation are virtually eliminated. The characteristics of carbides in the microstructure are appreciably changed; this has important effects on the pertinent properties.

The P/M high-speed steel products offer significant advantages in the manufacture and performance of tools. The advantages include superior grindability, machinability, size change uniformity, cross-sectional hardness uniformity, hardening response, and tool life under intermittent cutting conditions.

The observed property and performance advantages are rationalized in terms of the rapid solidification rate inherent in powder making, as well as in terms of basic microstructural characteristics of the P/M products.