Efficiently Removing Hydrogen of H-Supersaturated Liquid Steel in the Vacuum Degasser with Various Gas Injection Modes

Abstract

Hydrogen removal of H-supersaturated liquid steel produced in a hydrogen-rich environment in an industrial vacuum degasser (VD) is simulated here using a two-phase (argon–steel) Eulerian model. The dehydrogenation efficiency is evaluated for a series of ladle plug layouts and argon-purging modes. Increasing the plug number from the prototype double-plug of the ladle to four or slightly prolonging the degassing time of a triple-plug ladle enables to obtain the specified dehydrogenation efficiency and the end-point hydrogen level. Varying the plug position of the triple-plug ladle makes no significant difference in the dehydrogenation efficiency, which, however, is improved by adjusting the plug angle. For the triple-plug ladle, the non-uniform argon-purging mode improves the melt hydrodynamic conditions, but the optimal dehydrogenation performance is achieved in the uniform mode. The plug number has the greatest impact on the dehydrogenation efficiency compared to the other ladle designs considered. The high-efficiency dehydrogenation of H-supersaturated liquid steel in the VD can be achieved through using the quadruple plugs, or by using the triple plugs positioned at 0.57R, 0.57R, and 0.41R and the angles of 108.6° and 71.4°, with the uniform argon-purging flow rate.