| 摘要 |
PURPOSE:To accelerate decarburization and produce the extra low carbon steel in a short time by top-spouting the jet of the mixed gases of oxygen and inert gas after the blowing by pure oxygen. CONSTITUTION:Pure oxygen gas is blown in a reduced-pressure atmosphere. When the C content in molten steel becomes around 0.1%, the gases mixed with 50% of inert gas (Ar+N2 or N2) are top-blown. Furter at the end period of blowing where the C content becomes around 0.01%, the jet of the mixed gases of inert gas: O2 gas=75:25 are top-spouted to perform blowing, whereby the product is obtained. Namely, O2 and mixed gases are blown under a vacuum to accelerate the stirruing and diffusion in the molten steel simultaneously and at the same time expand the effective reaction interface on the gas side. As a result of this, the extra low-carbon steel may be produced at the rate of decarburization which is practically the same as that in conventional methods. |
