| 摘要 |
PURPOSE:To improve production efficiency and perform controlling of dynamic type blowing which reduces in-furnace residence time in converter blowing, by using the contents of P and S as control targets together with molten steel temperature and C content, and enhancing the accuracy in the control of the end point. CONSTITUTION:Prior to blowing point of a pure oxygen top blowing converter, the C, P and S contents of molten steel are measured simultaneously with the measurement of molten steel temperature by means of a converter sublance. Based on the thus measured values and the dephosphorization and desulfurization behaviors from the record of precedent charge, the C content CEP at the time when the target P content is attained and the C content CES at the time when the target S content is attained under the target molten steel temperature TA of the blowing end point are estimated and calculated. The oxygen supply amount O2C necessary for lowering these down to the minimum value CE out of these CEP, CES and the target C content CA of the blowing end point is calculated. On the other hand, the oxygen amount OL required for making the C content to the blowdown threshold value and the oxygen amount O2T necessary for making molten steel temperature to a target value are calculated, thence O2C, O2L, O2T are compared and cooling material is charged or slag making agent is added. |
