| 摘要 |
PURPOSE:To enable the double pipe which has firm integration function and has no distortions or the like to be obtained by mechanically pressure-welding inside and outside pipes then forming the metal bond through radiation beam welding partially along the axial direction. CONSTITUTION:An inside pipe 2 of stainless steel or the like and an outside pipe 3 of pressure-resistant steel or the like are pressure-welded at the faying parts 4. Beams are radiated to this double pipe 1 from the outside of the outside pipe 3 by means of electron beam welding or laser beam welding at the controlled welding width and depth of penetration to perform welding partially. At this time, the weld beads 5 melt so as to reach the faying parts 4 of the inside and outside pipes 2, 3 and further sufficiently enter the inside of the thickness of the inside pipe 3, to enable the metal bonding to be effected locally and continuously. This method makes it possible to accomplish firm bonding without giving any large welding strain to the double pipe and prevent deviation and local buckling. |
