Estimation method of phosphorus concentration in molten steel, converter blowing control device, program and recording medium

Abstract

The phosphorus concentration in molten steel during decarburization is estimated with high precision. The method for estimating the phosphorus concentration in molten steel according to the present invention is used to estimate the case where the dephosphorization treatment is not performed before the decarburization treatment using a converter or when the dephosphorization treatment is performed using a device different from the converter used for the decarburization treatment. The phosphorus concentration in molten steel during the decarburization treatment includes: an exhaust data acquisition step, obtaining exhaust gas composition and exhaust flow rate; a molten steel data acquisition step, obtaining molten steel temperature and carbon concentration in molten steel through sub-lance measurement; and A phosphorus concentration estimating step using data related to decarburization oxygen efficiency obtained using exhaust gas composition and exhaust gas flow rate, data related to exhaust gas composition, exhaust gas flow rate, molten steel temperature, and carbon concentration, and data related to decarburization treatment The dephosphorization rate constant is calculated according to the operating conditions, and the phosphorus concentration in the molten steel after the sublance measurement is estimated using the calculated dephosphorization rate constant and the phosphorus concentration in the molten steel at the beginning of the decarburization treatment.

Description

technical field [0001] The invention relates to a method for estimating phosphorus concentration in molten steel, a converter blowing control device, a program and a recording medium. Background technique [0002] In converter blowing, the control of the composition of the molten steel (especially the control of the phosphorus concentration in the molten steel) when the blowing is stopped is very important in the quality management of steel. In order to control the concentration of phosphorus in molten steel, the oxygen blowing amount, the input amount of auxiliary raw materials such as quicklime or scale, the input timing of the auxiliary raw materials, the height of the top blowing lance, the flow rate of top blowing oxygen and the flow rate of bottom blowing gas are generally used. Do the amount of operation. These operating amounts are often determined based on information obtained before blowing starts, such as target phosphorus concentration, molten iron data, and sta...

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Problems solved by technology

[0003] However, even under the same operating conditions, the reproducibility of the dephosphorization behavior in actual blowing is low, and there is a problem that the phosphorus concentration in molten steel varies greatly when the blowing is stopped.

Therefore, in the blowing based on the operation amount determined only based on the information obtained before the start of blowing as described above, it is difficult to suppress the variation in the phosphorus concentration in molten steel when the blowing is stopped.

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