STEEL SHEET FOR USE IN MARINE CONSTRUCTION IN POLAR REGIONS AND METHOD OF ITS PRODUCTION Russian patent published in 2024 - IPC C21D8/02 C22C38/02 C22C38/04 C22C38/06 C22C38/08 C22C38/12 C22C38/14 

FIELD: metallurgy.

SUBSTANCE: invention relates to production of steel sheet used for marine construction in polar regions. Sheet has the following composition, wt.%: C: from 0.06 to 0.09; Si: from 0.20 to 0.35; Mn: from 1.48 to 1.63; Nb: from 0.020 to 0.035; Ti: from 0.010 to 0.020; V: from 0.020 to 0.035; Ni: from 0.08 to 0.17; Al: from 0.015 to 0.040; P: less than or equal to 0.013, S: less than or equal to 0.005, N: less than or equal to 0.006, B: less than or equal to 0.0005, the rest is Fe and unavoidable impurities. As unavoidable impurities providing high quality of the steel sheet, the sheet contains H less than or equal to 0.0002, O less than or equal to 0.003, As less than or equal to 0.007, Sb less than or equal to 0.010, Sn is less than or equal to 0.020, Pb is less than or equal to 0.010, Bi is less than or equal to 0.010 and Ca is less than or equal to 0.005. Steel sheet composition satisfies the following conditions: carbon equivalent CEV is less than or equal to 0.39% and coefficient of sensitivity to cold cracks Pcm is less than or equal to 0.20%, where CEV=C+Mn/6+(Cr+Mo+V)/5+(Ni+Cu)/15, and Pcm=C+Si/30+Mn/20+Cu/20+Ni/60+Cr/20+Mo/15+V/10+5B.

EFFECT: steel sheet has the required set of properties, such as high strength, resistance to low temperatures, ease of welding and corrosion resistance, and also has good impact strength at low temperature aging.

9 cl, 5 tbl