ECONOMICALLY ALLOYED COLD RESISTANT HIGH-STRENGTH STEEL Russian patent published in 2019 - IPC C22C38/54 

FIELD: metallurgy.

SUBSTANCE: invention relates to the field of metallurgy, in particular to high-strength cold-resistant structural steels used for the manufacture of high-pressure vessels used to store compressed gases (air) in a wide temperature range, including in the Far North. Steel contains components in the following ratio, wt. %: carbon 0.23–0.27, silicon ≤ 0.30, manganese 0.30–0.60, chromium 0.90–1.15, nickel 2.40–2.80, molybdenum 0.40–0.50, vanadium 0.12–0.16, cerium 0.001–0.005, boron 0.0001–0.0010, sulfur ≤ 0.010, phosphorus ≤ 0.012, copper ≤ 0.10, iron and inevitable impurities – the rest. After heat treatment, the steel has a temporary resistance. σ_t within 1128–1275 MPa, yield strength σ_0.2 981–1128 MPa with a relative elongation of at least 13 % and impact strength at a temperature of minus 50 °C at least 39 J/cm² when testing specimens with a sharp notch.

EFFECT: after heat treatment, the steel has a temporary resistance in the range of 1128-1275 MPa.

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