HIGH-STRENGTH CORROSION-RESISTANT STEEL Russian patent published in 2019 - IPC C22C38/50 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, namely to high-strength corrosion-resistant steels of martensite-austenite class, and can be used for production of high-loaded parts of machines operating in wide temperature range. Corrosion-resistant steel contains, wt%: carbon 0.02–0.05, chrome 14.0–16.0, nickel 4.0–5.0, nitrogen 0.1 to less than 0.18, manganese <0.6, silicon ≤0.5, zirconium 0.06–-0.15, vanadium 0.03–0.15, iron and unavoidable impurities – the rest. Steel composition satisfies the following relationships: [C]+[N]<0.2 and Ni+0.5Mn+18N+30C+0.5Cu<9.5. Steel can additionally contain at least one element selected from the group: niobium in amount of up to 0.08 wt%, copper in amount of 0.01–0.2 wt%, tungsten in amount of 0.05–0.1 wt%, titanium in amount of 0.01–0.05 wt% and molybdenum in amount of 0.03–0.5 wt%.

EFFECT: providing required mechanical properties, namely tensile strength above 1,370 MPa, yield point not lower than 1,180 MPa, relative elongation of not less than 17 %, relative narrowing of not less than 60% and impact viscosity higher than 1,3 MJ/m², wherein steel is not subject to intergranular corrosion.

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