COMPOSITE BLEND FOR SMELTING ALLOYED STEELS Russian patent published in 2002 - IPC

FIELD: steelmaking. SUBSTANCE: blend contains iron-carbon alloy and oxide material. The former contains 0.05 to 20% alloying elements and 0.2 to 15% reducing metallic elements, and the latter contains 1 to 98% oxides of alloying elements present in iron-carbon alloy and 0.5 to 15% reducing metallic elements. Metallic reducers are elements whose oxygen affinity is equal to or higher than that of carbon, for instance B, Si, Ti, Al, Zr, Mg, Ca, Ba, P3M, or their mixtures. Appropriate alloying elements are chromium, manganese, boron, vanadium, silicon, titanium, aluminum, rare-earth metals, tungsten, molybdenum, cobalt, nickel, copper, or their mixtures. Iron-carbon alloy contains 0.02 to 5.5% metal-dissolved carbon and 0.1 to 3% free carbon with particle size 10^-5-10^-7 cm. Oxide material can contain 0.1 to 10% carbon-containing material in the form of metal carbides, soot iron, carbon black, graphite, amorphous carbon or their mixtures and 0.5 to 20% slag- forming components. Blend can contain, as iron-carbon alloy, preliminarily refined intermediate product with sulfur and phosphorus levels no higher than 0.01% each, oxygen level 0.005 to 0.10%, and nitrogen level 0.003 to 0.012%. Alloying element oxides can be in the form of preliminarily reduced materials with degree of metallization equal to or higher than 5%. Oxide material, alloying element oxides, carbon-containing and slag-forming components are in the form of agglomerate mixture. EFFECT: increased degree of alloying of steel with elements reduced directly in steel-smelting assembly fusion, reduced purity of metal, and reduced expenses. 9 cl, 2 tbl