| 摘要 |
PROBLEM TO BE SOLVED: To provide a bit for hot-boring, excellent in durability, wherein a tip is difficult to fall down and even in the case of falling down, the tip can easily be restored. SOLUTION: The bit for hot-boring has the structure, in which a build-up welding is performed to the tip 15 composed of a hardened build-up welding material on the boring surfaces 13, 14 of the bit body 11 used for boring a sleeve for molten metal tapping hole in a converter. The hardened build-up welding material is preferably a metal of stellite, heat resistant steel series, etc., having≥200HV hardness at 800°C. Further, the area occupied by the tip 15 is preferably 10-50% of the boring areas 13, 14 of the bit body 11. The bit for hot-boring of this invention has characteristics excellent in both of the durability and cost. COPYRIGHT: (C)2007,JPO&INPIT
|
