STEEL Russian patent published in 2014 - IPC C22C38/44 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, and namely to high-quality alloyed structural steels used for manufacture of strength members, gears and shafts, the surfaces of which are strengthened by carbonisation or nitro-carbonisation. Steel contains the following, wt %: carbon 0.14-0.16, manganese 0.25-0.50, silicone 0.17-0.25, chrome 1.35-1.65, nickel 4.20-4.40, molybdenum 0.30-0.40, cerium 0.007-0.009, lanthanum 0.001-0.005, aluminium 0.02-0.05, calcium 0.002-0.005, copper ≤0.20, sulphur ≤0.005, phosphorus ≤0.005, and iron is the rest. Ratio of calcium content to aluminium content is 0.13-0.15.

EFFECT: improving impact viscosity and hardness penetration of steel, solidness and hardness of a carburised layer, as well as brittle strength, ductility, endurance of bending fatigue and contact fatigue after carbonisation of a surface layer.

2 cl, 7 tbl