METHOD FOR CONTROLLING TEMPERATURE OF MOLTEN STEEL DURING REFINING BY COMPOSITE BLOWING IN CONVERTER

摘要

PURPOSE:To improve the hitting accuracy of the temp. of molten steel at the end of refining by blowing by setting a parameter for a control model, calculating the volume of oxygen required and the amount of a coolant thrown from information measured with a sublance and each measured value of the preceding steel during refining by blowing, and controlling refining by blowing. CONSTITUTION:A parameter for a control model expressing a refining reaction by blowing in a converter is set from plural operation factors of the preceding steel of the same kind. The volume of oxygen required and the amount of a coolant thrown are calculated by a prescribed equation on the basis of the control model, information measured with a sublance, the desired carbon content at the end of refining by blowing, the desired extent of temp. rise and the flow rate of gaseous O2 for top blowing, the flow rate of gas for bottom blowing and the height of a lance chosen for each kind of steel in the last stage of refining by blowing. The temp. of molten steel is controlled from the time when the measurement with the sublance is carried out to the end in accordance with the calculated values. By this method the rate of hitting the end temp. is increased.