Mechanism of Decarburization in RH Degasser

Abstract

Decarburization behavior in RH-Degasser was discussed on the basis of a comparison between simulation and operational result. In the simulation, decarburizations through Ar bubbles, CO bubbles and a free surface were considered. Furthermore, the difference in carbon concentration between the melt in the ladle and that in the vacuum vessel was also considered. As a result of the comparison, it was found that the contribution of the decarburization as CO bubbles to the total amount of decarburization is great. In order to step up the decarburization rate, increasing the circulation flow rate is effective. That is accomplished by reducing the atmospheric pressure in the vacuum vessel, injecting Ar at a deeper position, and increasing the Ar gas flow rate and the snorkel diameter. Increasing oxygen concentration is expected to be effective to promote decarburization. © 1995, The Iron and Steel Institute of Japan. All rights reserved.