Fracture-tough, high hardness stainless steel and method of making same

摘要

A cryogenically-formed and tempered stainless steel is provided having improved fracture toughness and corrosion resistance at a given hardness level, such as, for example, of at least about Rc 60 for bearing applications. The steel consists essentially of, in weight , about 21 to about 24 Co, about 11 to about 13 Cr, about 7 to about 9 Ni, about 0.1 to about 0.5 Mo, about 0.2 to about 0.3 V, about 0.28 to about 0.32 C, and the balance iron. The steel includes a cryogenically-formed martensitic microstructure tempered to include about 5 to about 10 volume post-deformation retained austenite dispersed therein and M.sub.2 C-type carbides, where M is Cr, Mo, V, and/or Fe, dispersed in the microstructure.