GEAR AND ITS MANUFACTURING METHOD Russian patent published in 2014 - IPC C22C38/60 C22C38/38 C22C38/22 C21D1/06 C21D9/32 F16H55/06 F16H55/17 

FIELD: metallurgy.

SUBSTANCE: gear is made from steel having the following chemical composition, wt %: C: 0.1-0.40; Si: 0.35-3.0; Mn: 0.1-3.0; Cr: less than 0.2; Mo:0.1 or less; P: 0.03 or less; S: 0.15 or less; Al: 0.05 or less; N: 0.03 or less; Fe and inevitable impurities are the rest. Gear is subject to carbonisation for formation of a carburised layer on the surface at low oxygen concentration, to cooling at low cooling rate and to hardening by heating with energy of high density for austenisation of a zone lying above the core part and gear parts without any austenisation of the core part, and quick cooling of the gear from such a state. Parts of the surface layer of the gear parts and the gear root part is represented by parts with the carburised layer; the rest part of the gear parts and some part of a disc part, which lies below the carburised layer, is represented by parts with a hardened layer, and the zone of the disc part, which lies deeper than the hardened layer, is a zone with a non-hardened layer.

EFFECT: produced gears have high hardness of surface and deep layers without its non-homogeneity and the shape of high accuracy.

14 cl, 11 dwg, 4 tbl, 1 ex