HOT-ROLLED STEEL SHEET AND HIGH-PRESSURE VESSEL MADE FROM IT Russian patent published in 2025 - IPC C21D8/02 C22C38/58 C22C38/54 C22C38/50 C22C38/48 C22C38/46 C22C38/42 B21D51/24 F16J12/00 F17C1/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, specifically to hot-rolled steel sheet with thickness of 5-150 mm, used as material for making vessels or boilers operating under high pressure in media containing hydrogen sulphide at temperatures from minus 60 °C to plus 110 °C. Sheet has the following chemical composition, wt.%: carbon is not more than 0.10, manganese 1.0-2.0, silicon 0.1-0.45, chrome not more than 1.0, nickel not more than 0.5, copper not more than 0.5, sulphur is not more than 0.005, phosphorus not more than 0.015, aluminium 0.02-0.06, titanium 0.001-0.15, niobium 0.001-0.15, vanadium 0.001-0.15, nitrogen not more than 0.010, boron not more than 0.0015, iron and unavoidable impurities – the rest. Steel sheet has the following mechanical properties at a temperature of plus 20 °C: yield point is not less than 360 MPa, ultimate strength is not less than 490 MPa, relative elongation is not less than 19%, hardness HB is not more than 220. Steel sheet has the following mechanical properties at a temperature of plus 110 °C: yield point of not less than 310 MPa, ultimate strength of not less than 440 MPa, hydrogen induced cracking (HIC) CLR of not more than 6%, resistance to hydrogen induced cracking (HIC) CTR of not more than 3%, resistance to hydrogen sulphide stress cracking (SSC) of not less than 80% of the minimum yield strength, KCV at minus 40 °C not less than 29 J/cm², KCU at minus 60 °C is not less than 39 J/cm².

EFFECT: improved operational properties of petrochemical equipment made from steel sheet.

6 cl, 2 tbl, 1 ex