CAST IRON AND A METHOD OF SMELTING THEREOF IN BLAST FURNACE Russian patent published in 1999 - IPC

FIELD: ferrous metallurgy. SUBSTANCE: high-quality cast iron with reduced level of harmful impurities, which is utilized to smelt and cast high- quality steel, is composed of, wt %: carbon 3.5-4.5, silicon 0.1-0.5, manganese 0.01-0.05, phosphorus 0.010-0.05, sulfur 0.005-0.015, titanium 0.01-0.03, chromium 0.005-0.04, copper 0.005-0.02, vanadium 0.01-0.03, iron - the balance. Method of smelting cast iron includes portionwise loading into blast furnace charge materials composed of agglomerate, pellets, fluxes, and coke; feeding oxidative and gas blowing; feeding steam; heating and reductively smelting charge; and discharging cast iron and slag. Iron-ore pellets and agglomerate utilized in the process contain less than 0.06% MnO and P₂O₅ and are characterized by slag basicity (CaO/SiO₂) 1.15-1.20. Theoretical burning temperature is set not lower than 2050 C using blowing parameters' control. EFFECT: reduced silicon and sulfur contents, provided small and isolated favorably shaped graphite inclusions, increased homogeneity of structure throughout casting cross-section, and decreased number of sulfide inclusions. 6 cl, 2 dwg, 1 tbl