PSEUDO-RIMMING STEEL PRODUCTION METHOD Russian patent published in 2007 - IPC C21C7/00 

FIELD: ferrous metallurgy, namely production of rimming steels.

SUBSTANCE: method comprises steps of melting semi-finished product with carbon content 0.03 - 0.06%; discharging it to ladle at adding aluminum; before discharging, preliminarily killing semi-finished product by means of silicon and manganese containing ferroalloys whose consumption is determined according to expression: Q simn = 11.9 x Mn b.d. - 3.14 Mn a.d. + 0.007 x Td. - 10.43 where Qsimn - ferroalloy consumption, t; Mnb.d. -manganese content in semi-finished product before discharging,%; Mn a.d. - manganese content in semi-finished product after discharging, %; Td - temperature of discharged metal before preliminary killing, °C. Then metal is discharged into ladle, killed with calcium, manganese and aluminum and it is fed to plant furnace-ladle where oxygen content in metal is improved by means of calcium additives at consumption determined according to expression: Qca = 3996.0 x Si -0.35 x O b.a. - 0.047 x O m + 497.0 where Qca -consumption of ferrocalcium wire, kg; Si -silicon content in metal before addition of ferrocalcium wire, %; Ob.a. - oxidation state of metal before addition of ferrocalcium wire; Om - oxidation state of metal. Then metal is fed to billet continuous casting machine for casting it at rate determined according to expression V = 0.023 x T ml - 0.23 x a/Al + 38.16, where Tml - temperature of metal in intermediate ladle, °C; Ca/Al - relation of calcium to aluminum in metal sample before feeding it to casting.

EFFECT: lowered content of non-metallic inclusions in metal, less loss of yield.

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