METHOD OF STEEL TREATMENT Russian patent published in 2001 - IPC

FIELD: ferrous metallurgy, particularly, ladle treatment of steel with controlled content of nitrogen. SUBSTANCE: method includes treatment of steel in ladle with refinery slag, continuous supply of oxygen after treatment of metal with refinery slag to metal surface with total specific consumption of 0.2-0.5 cu.m/t and blowing with neutral gas. Simultaneously with oxygen supply, reducing agents are introduced into metal bulk in amount ensuring maintenance of oxygen partial pressure at slat-metal boundary during oxygen supply equaling 10^-12-10^-15 atm. Metal is blown with neutral gas by bubbling. Slag is mixed with uniform intensity through entire volume of slag. EFFECT: increased gradient of oxygen partial pressure between slag-metal and gas-slag interfaces with higher total speed of nitrogen mass transfer to reduce nitrogen content in steel. 1 cl, 1 tbl, 1 ex