| 摘要 |
PURPOSE:To prevent cracking of a weld zone by reducing the welding speed at the starting end, once finishing welding just before the finishing end, then, welding the finishing end at the speed lower than the welding speed at the stationary time from the reverse direction and setting meeting port where welding finishing ends are superposed on each other at a part where machining strain is reduced. CONSTITUTION:At the time of welding the starting end, since the welding speed is lower than that at the stationary time, a projecting part is formed on the end face. After passing the starting end, the welding speed shifts to the stationary speed and a joining part is welded. Just before the finishing end, welding is once finished and then, this finishing end is welded at the speed lower than that at the stationary time from the reverse direction. A projecting part can be formed on the finishing end in the same way as on the starting end. In addition, it is considered that weld defects are easily caused on meeting part where the welding finishing end at the time of forward welding and the welding finishing end at the time of backward welding are superposed on each other and the occurrence of cracking in accordance with forming machining is feared and the position of can be set at the part where machining strain at the time of forming is reduced. By this method, cracking from the weld zone can be surely prevented. |
