| 摘要 |
PURPOSE:To extend the service life of a nozzle and to improve the quality of a cast slab by forming outer circumferential layer of peripheral wall near powder line part of the submerged nozzle with permeable porous refractory and executing molten metal supplying while blowing inert gas from the outer circumferential surface. CONSTITUTION:On the outer circumferential surface near the powder line of the submerged nozzle 3 arranged at lower part of a tundish 1, the permeable porous refractory layer 3B is formed and at the back face thereof, distributing groove 3C is set. The porous refractory layer 3B is formed, by which the refractory granule is made to about 10-30% porosity. Successively, at the time of supplying the molten metal, the inert gas of Ar gas, etc., is supplied from gas supplying pipe 3E to blow the inert gas from the outer circumferential surface of the nozzle 3. The inert gas prevents oxidation of the metal and also erosive action by the powder layer 5 to the outer circumferential surface of the nozzle 3 is restrained. By this method, the service life of the nozzle 3 is extended and the quality of the cast slab is improved. |
