OUT-OF-FURNACE STEEL TREATMENT METHOD Russian patent published in 2012 - IPC C21C7/00 

FIELD: metallurgy.

SUBSTANCE: method involves introduction to steel-pouring ladle of lime in quantity of 600…700-[S]₁ kg/t and pear spar in quantity of 150…180·[S]₁ kg/t as calcium-containing materials and primary aluminium ingots in quantity of 100…120·[S]₁ kg/t during metal tapping from steel-making unit. At metal supply to the furnace-ladle plant the metal in quantity of 300…350·[S]₂ kg/t and pear spar in quantity of 120…150·[S]₂ kg/t is added to the metal as calcium-containing materials, and aluminium rods in quantity of 60…80·[S]₂ kg/t are added to the metal as aluminium. At the end of out-of-furnace treatment there added are calcium-containing materials in the form of powder wire with ferrocalcium filler in quantity of 400…500·[S]₃ kg/t, where [S]₁ - sulphur content at the end of melting process in steel-making unit, [S]₂ - sulphur content when the metal is supplied to furnace-ladle unit, [S]₃ - sulphur content after extraction of the second portion of slag-forming materials.

EFFECT: use of invention provides the increase in desulphurisation degree, removal of non-metallic inclusions and globularisation of the rest inclusions in the metal.