PROCEDURE FOR MELTING RAIL STEEL IN OXYGEN CONVERTER Russian patent published in 2016 - IPC C21C5/28 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, particularly to a method for melting rail steel from phosphorus iron in oxygen converter. Method involves application of scull and leaving slag of preceding melting residues, pouring phosphorus cast iron, melt blowing with oxygen at variable position of tuyere, addition of loose materials and slag removal. Blowing is performed in three period till carbon content in metal 0.3…0.6 %, with three slag download at 5…6, 13…14 and 17…18 minute of blowing. At the beginning of each period the tuyere is located at the distance 2,500…3,000 mm from the metal bath surface level in converter with step-by-step lowering down to 1,000…1,200 mm at the end of period. Loose materials is added in portions during the first 5…6 minutes of blowing at each period, after that, short-term re-blowing is made with duration 30…90 seconds for metal temperature increase up to 1,640…1,650 °C. Tuyere is lowered with a step of 200…250 mm, while the number of lowering steps equals to 6…8.

EFFECT: invention provides production of high-quality rail steel with high carbon content, low oxidation level and low content of phosphorus.

6 cl, 1 tbl, 1 ex