| 摘要 |
PURPOSE:To clean the molten steel in a low solAl and low C region at a high degree in the secondary refining of the molten steel tapped from a steel making furnace to a ladle by adding a flux for accelerating the coalscence and floating of inclusions together with a required amt. of a deoxidizing agent to the molten steel under tapping. CONSTITUTION:A deoxidizing agent such as Al or Si is added to the molten steel under tapping to form the resulted product of deoxidation in an early time and to assure the time for the coalscence and floating till casting. The temp. drop during the tapping is decreased to lower the tapping temp. and to decrease the intrusion of the source for inclusions occuring in the erosion of refractories. Otherwise, the time for stirring in the secondary refining is extended as much as the temp. is decreased. The above-mentioned addition of the flux contributes to the fine dispersion of a low melting slag making agent into the molten steel by the stirring energy during tapping and the coalscence and floating of the resulted products of deoxidation such as Al2O3, SiO2 or the like to each other; at the same time, the adsorbed and absorbed layer of the floated inclusions is formed on the surface of the molten steel. A slag reducing agent for reforming oxidative slag may be added to the molten steel in the stage of tapping. |
