| 摘要 |
PURPOSE:To easily refine extra-low P steel in the manufacture of steel with a converter by thoroughly removing produced slag from the throat of the converter after finishing primary blowing and secondary blowing and by discharging molten steel into a pan. CONSTITUTION:Principal starting materials and initial subsidiary starting materials are charged into a converter, the feed of oxygen is started, and primary blowing is carried out while charging subsidiary starting materials as required. Produced slag is thoroughly removed from the throat of the converter by mechanical force or sucking force. Subsidiary starting materials for secondary blowing are then charged onto the molten metal after removing the slag, the feed of oxygen is started again, and molten steel having the desired temp. and composition is obtd. while charging subsidiary starting materials as required. Produced slag is thoroughly removed in a similar way. The molten steel free from slag is discharged into a pan to obtain extra-low P steel contg. <=0.005% P. It is desirable to regulate the C concn. of the molten metal after the primary blowing to 3.0-3.5% and the temp. of the molten metal to 1,400-1,450 deg.C. |
