STEEL FOR COLD TREATMENT OF METALS Russian patent published in 2011 - IPC C22C33/02 C22C38/24 B22F3/24 

FIELD: metallurgy.

SUBSTANCE: steel contains, wt %: 1.3 - 2.4 (C+N); where there are at least 0.5 C; 0.1-1.5 Si; 0.1-1.5 Mn; 4.0-5.5 Cr; 1.5-3.6 (Mo+W/2), but maximum 0.5 W; 4.8 - 6.3 (V+Nb/2), but maximum 2 Nb; and maximum 0.3 S, the rest - in essence is iron and impurities. Contents of (C+N) and (V+Nb/2) are balanced relative to each other so, that contents of these elements is in a region limited with coordinates A: [1.38; 4.8], B [1.78; 4.8], C: [2.32; 6.3], D: [1.92, 6.3], in the system of coordinates [(C+N), (V+Nb/2)], as shown at dwg. Upon quenching from temperature 980-1050°C and tempering microstructure of steel contains tempered martensite and 8-13 vol % of uniformly distributed in it MX-carbides, -nitrides and/or carbonitrides, where M in essence corresponds to vanadium, while X is carbon and/or nitrogen. At least 90 vol. % of carbides, nitrides and/or carbonitrides have equivalent diametre D_eq less, than 3.0 mcm.

EFFECT: steel possesses high wear resistance, viscosity, plasticity, hardness and hardenability.

22 cl, 15 dwg, 3 tbl