| 摘要 |
PURPOSE:To obtain a nozzle having excellent heat shock resistance, erosion resistance and wear resistance by forming an inner wall surface and an outer wall surface with the specific sintered bodies, in the nozzle for continuously casting Ni-Cr-Fe series steel material. CONSTITUTION:In the inner wall surface of the nozzle, at least the inner wall surface near the solidified point 3 of molten steel is constituted with the AlN sintered body 1 and the outer peripheral side of this AlN sintered body 1 is covered with the BN series sintered body 2 constituting the outer wall surface. In the inner wall surface, at least the inner wall surface near the solidified point of the molten steel is constituted with the AlN-BN sintered body having >=30wt% AlN content. A reason which AlN content in the AlN-BN sintered body is >=30wt.%, is to obtain sufficient erosion resistance to the molten metal, and the content is desirable to be >=50wt%. By this method, the steel material having good surface condition can continuously be cast over for long time. |
