| 摘要 |
In a method for making thin-walled metal pipes, application of a pre-deformation to a metal sheet by plastic bending longitudinally perpendicular thereto, and forming the metal sheet into a pipelike shape by use of the widthwise curvature resulting from residual stress of the metal sheet receiving such plastic bending, when its lengthwise curvature is reduced to zero, the metal sheet being joined together at its junction. |
