PROCEDURE FOR MELTING RAIL STEEL Russian patent published in 2010 - IPC C21C5/52 C21C7/06 

FIELD: metallurgy.

SUBSTANCE: procedure for melting rail steel consists in supply of metal scrap and liquid iron as metal charge into electric steel-melting furnace, in melting, in oxidising, in melting steel in batches, in tapping melt and leaving part of metal in furnace, in adding solid slag forming mixture, deoxidisers and alloying agents into ladle during tapping and in heat finishing steel by temperature and chemical composition at ladle-furnace aggregate. Liquid iron with contents of silicon not more, than 0.40% and phosphorus not more, than 0.09% at amount of 35-75% of charge weight is poured on slag and part of metal left in the furnace. Upon iron pouring there is charged metal scrap at amount of 25-65% and lime at amount of 3.0-4.2% of charge weight. During melt and oxidising there are carried out blow with gaseous oxygen at consumption rate 6000-15000 m³/h, addition of lime at amount of 0.4-1.3% of charge weight in portions by 50-200 kg and injection of carbon containing powder at rate of 15-65 kg/min. Concentration of FeO in slag is maintained within the interval 13-28%, while ratio CaO/FeO - within the range 2.6-4.5.

EFFECT: upgraded quality of steel, reduced consumption of lime and electric power.