METHOD FOR PRODUCTION OF HOT-ROLLED STEEL STRIPS Russian patent published in 2023 - IPC C21D8/02 C22C38/22 B21B1/26 

FIELD: metallurgy.

SUBSTANCE: invention can be used in production of hot-rolled steel with a two-phase ferrite-martensite structure, intended for production of machine parts and mechanisms with a guarantee of manufacturing products by cold deformation. Method for production of hot-rolled steel strip includes steel smelting, continuous casting into slabs, heating of slabs, hot rolling, cooling and winding of strips into coils. Steel is smelted containing, wt.%: carbon 0.04-0.09, silicon no more than 0.3, manganese no more than 1.5, the total content of chromium and molybdenum no more than 1.0, iron and inevitable impurities - the rest, moreover, the ratio of silicon to phosphorus in the smelted steel is 3-7. The end temperature of hot rolling is maintained in the range of 800-870°C, cooling is carried out for 5-25 s at a speed of 8-30°C/s up to a temperature of 650-800°C and then at a rate of 40-80°C/s up to a coiling temperature of not more than 300°C, with formation in the strips of a structure containing 70-90% ferrite and 10-30% martensite or martensite and untransformed austenite.

EFFECT: increase of yield of hot-rolled steel with a two-phase ferrite-martensite structure is provided by increasing the complex of mechanical properties: the anisotropy and suitability of the metal for further processing are improved.

2 cl, 2 tbl, 1 ex