Molten steel decarburization method in RH vacuum degassing equipment

摘要

PROBLEM TO BE SOLVED: To provide a molten steel decarburization method in an RH vacuum degassing apparatus capable of improving the decarburization progress estimation accuracy. A decarburization reaction rate during a decarburization process is determined as a differential equation of a linear reaction using a decarburization rate constant KC, a decarburization capacity coefficient ak is calculated using a CO gas generation rate k, and decarburization is performed. The decarburization rate constant KC is calculated using the capacitance coefficient ak, the carbon concentration in the molten steel is estimated using the mathematical model expressed by the above-defined differential equation, and the estimated carbon concentration in the molten steel reaches a predetermined target value. When determining the end of decarburization at the same timing, the CO gas generation rate k is obtained from the molten steel information and exhaust gas information in advance based on the relationship between the actual CO gas generation rate k in the past decarburization treatment, the molten steel information, and the exhaust gas information. A regression equation for obtaining the above is prepared, and the CO gas generation rate k is calculated by the prepared regression equation using the molten steel information and the exhaust gas information at the time of the decarburization treatment. [Selection diagram] Fig. 1