STEEL FOR COLD TREATMENT Russian patent published in 2006 - IPC C22C38/26 C22C33/02 

FIELD: metallurgy; steels for cold treatment.

SUBSTANCE: proposed steel has the following composition, mass-%: 1.25-1.75 (C+N); at least 0.5%C; 0.1-1.5% Mn; 4.0-5.5% Cr; 2.5-4.5% (Mo+W/2); maximum 0.5%W; 3.0-4.5% (V+Nb/2); maximum 0.5%Nb; maximum 0.3% S; the remainder being iron and unavoidable admixtures. Microstructure of steel in hardened and tempered state contains 6-13 vol-% of vanadium-enriched MX carbides, -nitrides and/or carbo-nitrides smoothly distributed in base of steel, where X is carbon and/or nitrogen; at least 90% of said carbides, nitrides and/or carbo-nitrides have equivalent diameter D_eq lesser than 3.0 mcm; total amount of other carbides, nitrides and/or carbo-nitrides does not exceed 1 vol-%. Proposed steel may be used for manufacture of tools by cutting, shearing and/or stamping in cold state or by molding metal powder.

EFFECT: improved characteristics; increased impact viscosity.

25 cl,, 9 dwg, 3 tbl