METHOD OF MICRO-ALLOYING AND MODIFICATION OF STEEL Russian patent published in 2004 - IPC

FIELD: ferrous metallurgy; micro-alloying and modification of steel. SUBSTANCE: proposed method includes introduction of deoxidizing agents and slag-forming agents into ladle containing molten metal, delivery of ladle to furnace-ladle unit, preliminary blowing of metal with carrier gas at fraction of 0.5-1.5 mm from aluminum alloy containing elements of alkaline-earth group at flow rate of 0.1-0.5 kg/ton of steel. Materials containing micro-alloying and modifying elements are introduced in form of oxides and/or fluorides of micro-alloying and modifying elements together with reductant; used as reductant is aluminum alloy containing elements of alkaline-earth group at consumption exceeding stoichiometrically amount required for complete reduction of micro-alloying and modifying elements by 5-10%. Aluminum alloy contains calcium, magnesium and barium at the following relationship of components, mass-%: aluminum, 70-75; calcium, 7-8; magnesium, 5-7; the remainder being barium. EFFECT: reduced contamination of steel by non-metallic inclusions; improved quality of steel. 2 cl, 1 tbl, 2 ex