| 摘要 |
PURPOSE:To prevent solidification and sticking of a molten metal on the surface of an immersion nozzle and to stabilize a casting operation by forming the wall surface of a molten metal immersion nozzle which is an immersion type molten metal charging nozzle of a material consisting essentially of BN and Si3N4. CONSTITUTION:Layers 24, 25 consisting essentially of BN or SiN3N4 or a mixture composed of both are coated on the outside and inside surface of the part to be dipped in a molten metal in an immersion type molten metal charging nozzle 3 for charging a molten metal into a casting mold, and are calcined by heating or the like to form a coating layer. A sleeve consisting essentially of BN or Si3N4 is fitted on the outside wall surface in the part to be dipped in the molten metal. The thickness of the BN and Si3N4 layer is made about severalmu-several hundreds mu. A billet having good quality is produced stably by using such nozzle. Since the molten steel does not stick on the nozzle 3, the cracking and failure of the nozzle 3 are prevented. |
