METHOD OF METAL DEGASSING IN LADLE Russian patent published in 2012 - IPC C21C7/10 

FIELD: metallurgy.

SUBSTANCE: method involves installation above the ladle of vacuum chamber with two branch pipes, submersion of two branch pipes of vacuum chamber under the metal level in the ladle, creation in vacuum chamber of residual pressure and supply via the pipeline to vacuum chamber branch pipe of inert gas under pressure. Prior to vacuum treatment there performed is deoxidation of metal and slag in the ladle till the content of free dissolved oxygen in the metal is not more than 3 ppm. Then, high-basic covering slag is introduced and metal desulphurisation is performed till sulphur content is not more than 20 ppm. Then, metal vacuum treatment is performed during 20…22 min at negative pressure of not more than 2.0 mbar with argon consumption in branch pipe of vacuum chamber of 4.2…5.6 l/(min*t).

EFFECT: use of invention provides the reduction of defect output and enlargement of branded range of molten metal sizes.