METHOD OF PRODUCING ESPECIALLY-LOW-CARBON STEEL Russian patent published in 2015 - IPC C21C7/00 C21C7/10 

FIELD: metallurgy.

SUBSTANCE: method includes the metal output to the steel-ladle at metal temperature at least 1630°C, vacuum decarburisation for 15-20 minutes, at pressure in the vacuum chamber below 0.2 kPa, then pressure in the vacuum chamber is increased to at least 20 kPa, then aluminium is added together with lime in quantity ensuring aluminium content in the metal at least 0.01% and slag basicity 0.8-1.4, then at least after 2 minutes aluminium is added on the basis of its content in metal at least 0.04%, metal is alloyed and treated by calcium in amount of 0.1-0.35 kg of calcium per 1 ton of metal, then steel-ladle is supplied for pouring.

EFFECT: exclusion of pulling of the immersed and casting sleeves during the steel casting due to reduced quantity of the non-metal inclusions, increased output of good metal due to large number of slabs cast under fixed conditions without abrupt casting speed change and significant level variation of the metal in the crystalliser.

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