PRODUCTION METHOD OF COLD-ROLLED SEMI-FINISHED ALLOY ELECTRIC STEEL Russian patent published in 2014 - IPC C21D8/12 H01F1/16 

FIELD: metallurgy.

SUBSTANCE: there performed are steel making, pouring, hot rolling, water cooling, strip rolling, etching, cold rolling and processing in a continuous multiple unit installation, steel containing the following components is molten, wt %: carbon 0.020-0.045, silicon 0.50-2.10, manganese 0.10-0.80, sulphur maximum 0.015, phosphorum maximum 0.015, chromium maximum 0.10, nickel maximum 0.15, copper maximum 0.15, aluminium 0.10-0.60, nitrogen 0.002-0.010, iron and unavoidable impurities making the rest; final deformation of a strip in a finishing mill group of a continuous wide-strip mill is carried out under the temperature of process workpiece input - maximum 1070°C, rolling end temperature is kept at the level of 780-880°C, accelerated cooling is performed at the rate of 20-45°C/s, reeling temperature is set at the level of 480-640°C, recrystallisation annealing of cold-rolled mill products in the continuous multiple unit installation is carried out with partial decarbonisation up to the carbon content of 0.012-0.030%, under the temperature of 780-820°C, afterwards tempering of steel is performed under the temperature of 450-600°C for 150-250 seconds. Metal killing with cobbing of 0.5-5% follows the thermal treatment of the cold-rolled mill products if necessary.

EFFECT: higher quality of rolled metal due to the achievement of stable mechanical properties with full compliance with requirements to magnetic properties.

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