METHOD OF PRODUCING CARBON STEEL Russian patent published in 1999 - IPC

FIELD: ferrous metallurgy; may be used in production of carbon steel, for instance, in open-hearth furnaces. SUBSTANCE: method includes deoxidizing of metal before tapping from furnace to remove superequilibrium oxygen by portional additions of lumpy materials and subsequent finishing. To remove superequilibrium oxygen from metal, use is made of lumpy materials with density of not less than that of molten metal, and materials containing elements possessing affinity to oxygen not lower than that of aluminum. Reaction of the latter with oxygen is carried out just after removal of calculated superequilibrium concentration of oxygen to carbon. Lumpy materials are used in the form materials, ferroalloys, alloying compositions, pig iron, metal scrap in the amount required for removal of calculated superequilibrium concentration of oxygen. Elements possessing affinity to oxygen not lower than that of aluminum are used in the form of aluminum, titanium, boron, alkali-earth metals and/or their alloys in the amount required for maintaining the equilibrium concentration of oxygen with carbon prior to beginning of metal finishing. Elements possessing the affinity to oxygen not lower than that of aluminum maybe added in shells ensuring their immersion to under slag. EFFECT: reduced losses of deoxidizing agents and alloying elements by 7%, higher quality of metal due to reduced non-metallic inclusions up to 60%, improved mechanical properties and yield of high-grade steel. 4 cl, 1 tbl