CASTING AUSTENITIC HIGH-STRENGTH CORROSION-RESISTING IN INORGANIC AND ORGANIC ENVIRONMENTS CRYOGENIC STEEL AND METHOD OF ITS PRODUCTION Russian patent published in 2017 - IPC C22C38/58 C21D1/00 

FIELD: metallurgy.

SUBSTANCE: obtain the steel melt, pour it into the mould to obtain the casting and cool it. The steel casting has the following composition, wt %: C 0.05-0.07, Cr 18.0-20.0, Ni 5.0-7.0, Mn 9.0-11.0, Mo 1.4-1.8, Si 0.25-0.35, Cu 3.6-4.0, N 0.14-0.22, Al 0.015-0.035, B 0.05-0.1, S ≤0.0025, P≤0.010, Sn≤0.005, Pb≤0.005, Bi≤0.005, As≤0.005, Fe is the rest. The nitrogen content is related to the contents of chromium, copper, nickel and manganese by the following relationships: at the ratio (Cr+5Cu)/(Ni+Mn)≤2.50, the nitrogen content is N = 0.14-0.18%, and at the ratio (Cr+5Cu)/(Ni+Mn)>2.50, the nitrogen content is N = 0.18-0.22%. The casting mechanical processing, its subsequent heating up to the temperature of 1150-1250°C, and the homogenization of at least 2 hours and hardening to the solid solution with the ferrite content in the structure of steel not more than 5%, is carried out.

EFFECT: required strength and corrosion properties in the inorganic and organic media in the cryogenic temperatures field.

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