The molten steel decarburization method in RH vacuum degasser

摘要

PROBLEM TO BE SOLVED: To provide a molten steel decarburizing method in a RH vacuum degassing device for estimating the carbon concentration of molten steel during decarburization with high accuracy, and stopping decarburization at adequate timing.;SOLUTION: A model to calculate the flow-out rate of carbon from the entire molten steel is constituted by using a numerical model to express the rate of change of the carbon concentration in the molten steel in a vacuum tank 1 and the rate of change of the carbon concentration in the molten steel in a ladle 2 by a differential equation using the carbon concentration in the molten steel in the vacuum tank 1 and the carbon concentration in molten steel in the ladle 2, the pressure in the vacuum tank 1, the oxygen concentration in the molten steel, and the mass of the molten steel in the ladle 2, and the mass of the molten steel in the vacuum tank 1. The carbon concentration in the ladle 2 is secularly estimated by an observer of performing correction by adding the value obtained by multiplying the error between the calculated carbon flow-out rate from the entire molten steel by the model and the calculated carbon flow-out rate in exhaust gas by a coefficient to the rate of change of the carbon concentration in molten steel in the vacuum tank 1 of the model and the rate of change of the carbon concentration in the molten steel in the ladle 2, respectively.;COPYRIGHT: (C)2006,JPO&NCIPI