| 摘要 |
PURPOSE:To enable fine adjustment of SolAl in molten steel without decreasing Al yield by performing high-speed Al addition into tundish intermittently at the time of adding Al into the molten steel which has undergone precedent deoxidation. CONSTITUTION:After the precedent deoxidation of molten steel by Al, Si, Mn, etc. during tapping, the oxygen level in the molten steel is measured and the required Al amount for obtaining the target SolAl is obtained. Along with this, the intermittent charging periods are determined based on the speed of casting, the diameter of the Al wire used, the rate of its addition, etc. These intermittent addition patterns are made large in the intervals of addition and dwell as far as the mixing effect of the Al added permits, but 10 seconds is the upper limit from e.g. the figure. As a result of this, the higher speed of addition per time of the Al wire may be achieved and the oxidation loss is decreased, in addition to which the correct control of SolAl value becomes possible as shown in the figure. |
