| 摘要 |
PURPOSE:To form a weld bead to good-looking bead of stable quality at high work efficiency and at low cost in pressure welding and electric resistance welding a web material and a flange material by arranging bead forming rolls at the weld zone. CONSTITUTION:In electric resistance welding a web material W to flange materials F, F, pressure welding rolls 1, 1, four bead forming rolls 2, and web supporting guides 3 are arranged on a straight line substantially. While letting flow high frequency current to the web material W and flange material F, the materials are pressure welded by pressure welding rolls 1, 1 and then welding is performed by electric resistance welding. The bead generated at the weld zone at this time is formed by bead forming rolls 2. Thus, no bead of bad-looking that can cause lowering of corrosion resistance after painting is formed at the weld zone. |
