STRUCTURE STEEL OF HIGH IMPACT RESILIENCE AT CRYOGENIC TEMPERATURE Russian patent published in 2011 - IPC C22C38/16 C22C38/14 

FIELD: metallurgy.

SUBSTANCE: steel contains carbon, silicon, manganese, nickel, niobium, titanium, calcium, cobalt, copper, sulphur, phosphorus, tin, antimony, iron and unavoidable impurities at following ratio of components, wt %: carbon 0.05 - 0.10, manganese 0.30 - 0.60, silicon 0.15 - 0.35, nickel 5.50 - 6.50, niobium 0.02 - 0.06, titanium 0.01 - 0.03, calcium 0.001 - 0.005, cobalt 0,01 - 0.5, copper not over 0.30, sulphur not over 0.005, phosphorus not over 0.010, tin not over 0.005, antimony not over 0.005, iron and unavoidable impurities - the rest. Ratio of summary contents of niobium and titanium to carbon is 0.6-0.9, ratio of calcium to sulphur is not less, than 1.0, while summary contents of tin, antimony and phosphorus is not over 0.018.

EFFECT: raised cold resistance of steel at maintaining strength and efficient alloying with nickel.

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