| 摘要 |
PROBLEM TO BE SOLVED: To surely prevent intrusion of air from a connecting part only by performing slight modification to the conventional structure, in the connection structure connected by connection of a circulating-flow tube with an immersion tube which are projectingly provided to the bottom part of a vacuum-degassing vessel. SOLUTION: The inner peripheral-upper edge of a second refractory material 5 lined on the immersion tube 1 and the inner peripheral-lower edge of a first refractory material 11 of the circulating-flow tube, are cut and notched and a recessed part 18 where the notches are continuously connected when the immersion tube 1 is connected to the circulating-flow tube 2, is formed, and in this recessed part, a third refractory material 19 is fitted. The air to intrude from the outer part is blocked by the third refractory material 19 to prevent an increase in nitrogen concentration caused by mixing of the air into molten steel. COPYRIGHT: (C)2009,JPO&INPIT |
