METHOD TO PRODUCE HOT-ROLLED WIDE-STRIP COIL STOCK Russian patent published in 2014 - IPC C21D8/02 C22C38/38 B21B1/26 

FIELD: metallurgy.

SUBSTANCE: stock is made of steel containing wt %: 0.07 carbon, 0.03 silicon, 0.4÷1.6 manganese, 0.03 chrome, 0.03 nickel, 0.012 sulphur, 0.014 phosphorus, 0.047 aluminium, 0.04 copper, 0.018 titanium, 0.007 nitrogen, 0.02÷0.09 niobium, 0.003 vanadium, which is exposed to rolling, accelerated cooling and winding of strips into a coil stock, at the same time if strip thickness is up to 5 mm inclusive, they use steel with actual content of manganese and niobium, if thickness of rolled steel is from 5.01 mm to 12 mm inclusive - steel with content of manganese more than 1.5 times and content of niobium more than 1.2 times more than in production of rolled stock with thickness of up to 5 mm, with thickness of rolled steel from 12.01 mm to 16 mm, inclusive - steel with content of manganese more than 1.9 times and content of niobium more than 1.5 times than in production of rolled steel with thickness of up to 5 mm, at the same time temperature of end of rolling is maintained as lower than the temperature Ar₃÷(Ar₃-30)°C, winding temperature is provided as lower than Ar₁ by 100÷150°C, calculating values of Ar₃ and Ar₁ using the following formulas: Ar₃=879.2-94.24[C]-21.13[Si]-25.56[Mn]+47.71[Cr]+16.44[Ni]; Ar₁=729.2-9.24[C]+12.13[Si]-15.56[Mn]+17.71[Cr]-46.44[Ni].

EFFECT: improved consumer properties and strength properties of rolled metal.

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