METHOD FOR PRODUCTION OF PLATE STEEL FROM LOW ALLOYED STEEL FOR PIPES Russian patent published in 2019 - IPC C21D8/02 C22C38/54 B21B1/26 

FIELD: metallurgy.

SUBSTANCE: invention relates to the field of ferrous metallurgy, in particular to production of plate steel from low alloyed steel of high strength used in production of electrically welded longitudinal pipes for construction of main oil and gas pipelines in northern latitudes. To ensure technical result steel is melted, containing in wt%: carbon 0.04–0.08, manganese 1.65–1.95, silicon 0.10–0.30, aluminum 0.02–0.05, chrome 0.01–0.30, nickel 0.80–1.00, copper 0.35–0.50, molybdenum 0.10–0.20, titanium 0.010–0.030, niobium 0.020–0.050, vanadium 0.001–0.050, nitrogen 0.001–0.008, sulfur not more than 0.005, phosphorus not more than 0.015, iron – balance, casting on workpieces, austenitization at 1,120–1,200 °C, preliminary deformation at 940–1,090 °C, further cooling of roll in air to final deformation beginning temperature, final deformation at 720–770 °C and accelerated cooling of rolled sheet at a rate of not less than 12 °C/s in temperature range from not less than 700 °C to 630–670 °C with its subsequent slow cooling in pile.

EFFECT: increased cold resistance at maintaining sufficient level of strength and plastic properties.

1 cl, 4 tbl