METHOD OF MAKING LOW-CARBON CONSTRUCTIONAL STEEL Russian patent published in 2003 - IPC

FIELD: ferrous metallurgy; making low-carbon constructional steels for manufacture of pipes working in aggressive media at low temperatures. SUBSTANCE: proposed method includes melting metal in steel-making unit, deoxidation and alloying, introducing manganese oxides together with carbon-containing reductant at ratio of (8.8-9.2): 1 so that content of manganese in metal before tapping it in ladle is 0.1-0.2 of content required in finished steel. Then, metal is trapped into ladle and manganese oxides with aluminum-containing reductant are introduced. Calcium oxides are introduced in ladle in form of refining mixture with barium oxides at ratio of 8.5 to 9.5. Ratio of manganese oxides fed to ladle, aluminum-containing reductant and refining mixture is (70-75): (8- 10): (17-20). Treatment of molten metal in ladle is performed by slag formed after reduction of manganese by aluminum. EFFECT: improved quality of metal due to reduction of nonmetallic inclusions. 1 tbl, 1 ex