| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a welding method by which a seam weld zone having excellent characteristics is obtained even if a heat source having high energy density is used by improving butting precision in both side end parts of a metal sheet using a simple tool when an open pipe is welded. SOLUTION: A cylindrical open pipe having 200-2000 mm length and 0.6-4 mm thickness in which the both side end parts of the metal sheet face each other is formed, an interval between a clamp which restricts the both side end parts from the outside and a backing die which restricts the both side end parts from the inside is set at 1.2-1.8 times the thickness of the metal sheet, the both side end parts are butted by pressurizing side faces of the open pipe from the outside, and the both side end parts are welded using laser welding or plasma welding.</p> |
