composition for steel with a manganese content of not less than 8 wt. in electric arc furnaces with basic feed

摘要

In melting processes for steel containing not less than 8 % by weight of manganese in electric arc furnaces with basic lining, the deoxidation of impurities is effected, with simultaneous smelting of the raw material, by adding limestone as slag former to the furnace hearth and by subsequent charging of raw material together with the iron ore to the limestone. After removal of the refining slag and charging with slag formers before the melt is alloyed with manganese, the deoxidation of the molten metal by diffusion takes place for at least 5 minutes with a mixture which is composed of aluminium, freshly prepared unslaked lime, a carbonaceous material, ferrosilicon and fluorspar and which is charged on top of the slag. The alloying of the molten metal with manganese, using ferromanganese, takes place with simultaneous deoxidation by diffusion, using a mixture which is composed of freshly prepared unslaked lime, a carbonaceous material and ferrosilicon: in this case, ferromanganese and the mixture are charged to the top of the slag simultaneously in 3 to 4 passes and, after at least 5 minutes after addition of the last charge of ferromanganese and the mixture have elapsed, the subsequent deoxidation by diffusion with the mixture to be charged on top of the slag is carried out, the mixture being composed of freshly prepared unslaked lime, a carbonaceous material and aluminium, after which ... Original abstract incomplete.