| 摘要 |
PROBLEM TO BE SOLVED: To provide the pushing-up roll with a shape effective to suppress an edge wave and to control the butting state of both edge parts and the manufacture of the welded tube using the same. SOLUTION: This manufacturing device is constituted so that while a strip metal is being continuously formed to a tube shape by plural forming stands and both edge parts α are subjected to butt welding. In this case, the shape of the pushing-up roll 8 to be mounted on a pushing-up roll device arranged between final fin pass rolls and squeeze rolls, is in the following range. 0.1D0 <=R<=0.5D0 , 0.15D0 <=D, 0.05D0 <=W, where D0 is the outside diameter of the tube (mm), R is the caliber diameter of the pushing-up roll (mm), D is the maximum diameter of the pushing-up roll (mm), W is the width of the pushing-up roll (mm). |
