| 摘要 |
PURPOSE:To continuously cast the weak deoxidized steel corresponding to rimmed steel and semikilled steel by forming rotating film flows of strip-form molten steel having a width in the bath depth direction on the entire circumferential surface at the freezing interface in the upper part of the bath in the mold and forming the frozen layer of less element thickening over the entire surface of the slab surface layer. CONSTITUTION:After molten steel 6 is poured into a mold 7 from the molten steel spouting port 13 of a nozzle 11, linear motors (rotating film flow formers) 8, 8' are disposed respectively on both longer sides of the mold 7. Next, the motors 8, 8' are run to form the rotating film flows 3 of strip form of about 10-20mm. in thickness at the freezing interface 2 from the freezing initiation point (molten metal surface 1) up to the position where the freezing thickness above the scale-off amount (about 0.7-2mm.) is formed. Namely, the film-form rotating molten steel flows (black framed parts 3) are formed only on the entire circumference of the freezing interface 2 of the molten metal surface 1 to form the frozen layer 5 where the element concentration is below the production limit of the nuclei of air bubbles in the surface layer of the resultant slab 4. |
