HOT-ROLLED I-STEEL FOR ROLLING AND FORMING BLANKS OF SPECIAL SHAPE FROM IT AND METHOD FOR ITS MANUFACTURING Russian patent published in 2023 - IPC C22C38/12 C22C38/08 C22C38/06 C22C38/04 C22C38/02 C21D8/00 

FIELD: metallurgy.

SUBSTANCE: invention is related to hot-rolled I-beam steel used in construction of offshore oil platforms. Hot-rolled I-beam steel contains the following chemical components, wt.%: С: 0.04-0.08, Si: ≤0,25, Mn: 1.25-1.45, V: 0,04-0,10, Ni: 0,2-1,0, Р: ≤0.02, S: ≤0.01, Nb: 0.02-0.06, Al: 0.02-0.06, N: ≤0.015, О: ≤0.005, the rest is Fe and unavoidable impurities. I-beam steel has a flange thickness of 18-24 mm, the yield strength of the upper and lower shelves is greater than or equal to 420 MPa, the energy of transverse impact at a temperature of -40°C is greater than or equal to 34 J and the energy of longitudinal impact at a temperature of -60°C is greater than or equal to 120 J.

EFFECT: low-temperature resistant hot-rolled I-steel for marine equipment is obtained, which has the required mechanical properties, easy to produce in industrial conditions and reduces the requirements for rolling equipment.

7 cl, 1 dwg, 3 tbl, 3 ex