PRODUCTION METHOD OF ULTRA LOW CARBON COLD-ROLLED ISOTROPIC ELECTRICAL STEEL Russian patent published in 2014 - IPC C21C7/00 C21D8/12 

FIELD: metallurgy.

SUBSTANCE: method involves combined metal blowing in a converter, decarburisation of metal in vacuum, steel alloying by ferrosilicon refined from carbon, continuous pouring of liquid metal into slabs from a lined steel pouring ladle through an intermediate ladle to a continuous-casting machine (CCM) crystalliser using a slag-forming mixture in the latter, which contains not more than 1.5% of carbon, hot rolling, normalising annealing, etching, cold rolling till final size and final annealing. During the alloying process there added is ferrosilicon with carbon content of not more than 0.02% in the quantity providing silicon content in the melt within 0.5÷3.2%; pouring of liquid metal into slabs is performed with addition to the intermediate ladle of a heat insulating mixture with carbon content of not more than 2%. With that, a steel pouring ladle with the main lining, in which carbon content is not more than 2%, is used.

EFFECT: invention allows obtaining low content of carbon in finished isotropic steel and providing uniformity of mechanical and electromagnetic properties of a strip along and across the rolling direction.

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