| 摘要 |
FIELD: methods of making bearing steels in electric arc steel melting furnaces. SUBSTANCE: proposed method includes charging scrap, lime and sinter into electric arc steel melting furnace as slag-forming materials, melting these materials, feeding gaseous oxygen for oxidation of carbon at oxidizing period, adding sinter for dephosphorization of metal, forced slag flushing, performing reducing phase, adding iron in the course of process and tapping steel into ladle. Lime and sinter are charged in the amount of 18 to 21 kg per and 11 to 15 kg per ton of steel, respectively. Molten iron is poured in the amount of 22 to 24% of mass of charge at power requirement of 285 to 340 kWh per ton of charged scrap; after melting, temperature in furnace is maintained by 120 to 160 C higher than liquidus temperature. Gaseous oxygen for oxidation of carbon is fed at rate of 14 to 19 cu nm per ton of steel. For dephosphorization of metal, 19 to 20 kg of sinter and 15 to 17 kg of lime are added per ton of steel followed by forced slag flushing in the amount no less than 2/3 of total initial mass. Proposed method reduces contamination of steel by nonmetallic inclusions (oxides, sulfides and globules). EFFECT: reduced melting time; reduced power requirements. 1 tbl |
