| 摘要 |
PURPOSE:To obtain dead soft steel in a short time without degassing in a slagless converter steel making method by evacuating the inside of a converter when the content of C in the end period of refining decreases. CONSTITUTION:A hood 2 is installed in a converter 1 via a sealing device 3, and O2 is blown through a lance 4 into the molten iron in the converter 1 which is thoroughly decreased of Si, P, S, etc. by preliminary refining so that only the decarburization refining is accomplished. When the content of C in the molten iron decreased to <=0.02%, a dust collector connected to the hood 2 is changed over to a steam injector and the inside of the converter is evacuated. Dead soft steel contg. 0.001-0.005% C is thus obtained. The decarburization effect considerably higher than the decarburization effect of the case in which the inside of the converter is not evacuated is obtained according to the above-mentioned method. If an inert gas is blown into the molten iron in the converter in parallel with the evacuation, the reaction of decarburization is additionally accelerated. |
