| 摘要 |
PURPOSE:To refine molten steel to a desired compsn. outside a furnace by shifting the steel to a container such as a ladle; adding Al, Si, etc. to raise the steel temp. by heat of oxidation with oxygen; blowing an inert gas to stir the steel and clean it; and adding a deoxidizer and a compsn. regulating alloy. CONSTITUTION:Molten steel is shifted from a melting furnace to ladle 1 provided with porous plug 3 at bottom 2. While introducing an inert gas such as Ar through plug 3 at a rate of 5 l/min, Al; 0.4-0.6% and Si; about 0.5% are added to the steel. Oxygen is then sprayed upon the steel surface through lance 4 and blown into the steel through pipe 5 to oxidize the Al and Si, thereby raising the steel temp. by heat of the oxidation. The formed Al2O3 and SiO2 are allowed to rise to the steel surface with inert gas bubbles and separated. A deoxidizer, a compsn. regulating ferro-alloy, etc. are finally added to deoxidation-refine the steel to a desired compsn. Lining refractory of the melting furnace is scarcely demaged, elongating the service life. |
