HOT-ROLLED ROUND STOCK Russian patent published in 2012 - IPC C21D8/06 C22C38/22 C22C38/40 C21C5/52 

FIELD: metallurgy.

SUBSTANCE: rolled stock is made from alloyed steel containing the following, wt %: carbon 0.42-0.50, manganese 0.50-0.80, silicon 0.17-0.37, chrome 1.20-1.50, molybdenum 0.50-0.80, vanadium 0.30-0.50, nickel 3.70-4.20, aluminium 0.020-0.050, iron and inevitable impurities are the rest. Steel contains the following components as impurities, wt %: phosphorus not more than 0.025, sulphur not more than 0.025, copper not more than 0.30. Rolled stock has hardness of not more than 241 HB, macrostructure as per central porosity, spot non-homogeneity, segregation square as per each type is maximum 2, below-shrinkage segregation is 1, decarburised layer of not more than 1.5% of diameter, skin holes and intergranular cracks are not allowed.

EFFECT: possibility of manufacturing from alloyed steel of heat-treated hot-rolled round stock of large diameters with characteristics of macrostructure, which correspond to high-alloy steel.

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