Niobium in tool steels

This review initially outlines the possible roles of niobium, as an alloying element in tool and high speed steels, on hardenability, toughness, dimensional stability, resistance to softening and wear resistance. Then the anticipated or known effects of niobium in cold work, hot work and high speed tool steels are discussed, taking into account its characteristics as a grain refining and carbide forming element. Emphasis is placed upon the development work already performed, particularly, in relation to high speed tool steels. (AU)