METHOD FOR PRODUCTION OF COLD-ROLLED STRIPS FROM IF-STEEL Russian patent published in 2022 - IPC C21D9/46 C21D8/02 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, namely to methods for the production of cold-rolled strips of ultra-low-carbon IF-steels, which can be used for the manufacture of stamped products of a particularly complex shape. The method for production of cold-rolled strips from IF-steel includes steel smelting, casting, hot rolling to obtain strips, etching, winding strips into rolls, cold strip rolling, recrystallization annealing in a continuous annealing unit and pinch rolling. Steel is smelted containing, wt. %: C 0.003-0.006, Si 0.015-0.030, Mn 0.06-0.15, Al 0.01-0.06, Ti 0.04-0.06, Fe and unavoidable impurities being the rest, calcium and magnesium are introduced into it as modifiers of non-metallic inclusions, the winding of strips into rolls is carried out at a temperature of at least 650°C, while steel contains non-metallic inclusions of complex composition, no larger than 5 microns, containing aluminum, calcium, magnesium, titanium and oxygen, and the total content of calcium, magnesium, titanium and aluminum in inclusions corresponds to the equation ([Ca]+ [Mg]+[Ti])/[Al] ≥1, where [Ca], [Mg], [Ti] and [Al] are the content of calcium, magnesium, titanium and aluminum in nonmetallic inclusions, respectively.

EFFECT: invention provides increased corrosion resistance while maintaining high ductility, formability and stability of strength characteristics.

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