| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an immersed pipe of a vacuum degassing apparatus capable of controlling penetration of air outside a castable layer through the castable layer inwardly in its radial direction, and transfer thereof to a molten metal passage side, controlling the nitrogen component contained in a molten metal such as a molten steel, and enhancing the quality of the molten metal such as the molten steel. <P>SOLUTION: A refractory layer 3 includes an upper refractory layer 4 and a lower refractory layer 5. A projecting part 7 provided on any one of the upper refractory layer 4 and the lower refractory layer 5 is provided on a boundary area 6 between the upper refractory layer 4 and the lower refractory layer 5, and a recess 8 which is provided on the other of the upper refractory layer 4 or the lower refractory layer 5 and fitted to the projecting part 7 is provided on a boundary area 6 between the upper refractory layer 4 and the lower refractory layer 5. By fitting the projecting part 7 to the recess 8, the advance of molten metal in the boundary area 6 between the upper refractory layer 4 and the lower refractory layer 5 is controlled. <P>COPYRIGHT: (C)2013,JPO&INPIT |
