| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of manufacturing a stepped metallic tube by which the occurrence of seizure is suppressed when cold expanding a tube. SOLUTION: A plug 10 for expanding a tube including a tapered part 20 having the surface the outside diameter of which is gradually enlarged from the top end toward the tail end and a stellitic build-up layer which is formed on the surface of the tapered part is prepared. Successively, the plug 10 is inserted into the metallic tube 50 and the tube end of the metallic tube 50 is cold expanded. After expanding the tube end, the plug 10 is pulled out of the metallic tube 50. In the cold expansion of the tube, by forming a stellite build-up layer on the surface of the plug 10, the seizure is prevented equally to the coating film of a conventional cemented carbide and by coating method. COPYRIGHT: (C)2009,JPO&INPIT
|
