| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for selecting a sleeve of a tapping port according to the drilling ability of a drilling bit, to provide the sleeve of the tapping port, and thereby to shorten a disassembling period of time while suppressing the wear of an edge body of the drilling bit. <P>SOLUTION: When D (mm) is defined as a diameter of an end part of the drilling bit to be mounted on a drilling machine to be used for disassembling the sleeve of the tapping port which has been attached to a vessel for the molten metal, and T (N×m) is defined as the maximum torque of the drilling bit, which acts on the sleeve of the tapping port in the circumferential direction, the sleeve of the tapping port has such a compressive strength C (MPa) as to satisfy C≤(T/D×1,000+2,000)/300 and 10≤C≤120. When S (cm<SP>2</SP>) is defined as a contact area of the edge body of the drilling bit with the sleeve of the tapping port and IE (J) is defined as the maximum impact energy of the drilling bit, which acts on the sleeve of the tapping port in the axial direction, the sleeve of the tapping port has such a bending strength M (MPa) as to satisfy M≤(IE/S×10,000-2,000)/3,000 and 2≤M≤18. <P>COPYRIGHT: (C)2011,JPO&INPIT |
