NITRATED STEEL FOR GEAR WHEELS Russian patent published in 2015 - IPC C22C38/24 

FIELD: metallurgy.

SUBSTANCE: steel has the following component ratio, wt %: carbon of more than 0.40 to 0.43, silicon 0.17-0.37, manganese 0.50-0.65, chrome of 1.10 to less than 1.20, molybdenum 0.20-0.30, vanadium 0.05-0.08, nickel ≤0.30, copper ≤0.25, sulphur ≤0.020, phosphorus ≤0.020, and iron is the rest.

EFFECT: specified stable characteristics both of a nitrated layer: its thickness, hardness, structural viscosity and obtaining strength and viscosity of the core at satisfactory processibility and accuracy of large-sized gear wheels and increasing resistance of bending and contact fatigue of a nitrated layer and the whole part.

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