| 摘要 |
PURPOSE:To generate no welding defect in each end part, by welding the end part of the upstream side and the downstream side in the weld advancing direction, by each welding condition which is different from that of the center part, when MIG-welding the butt part of an open pipe. CONSTITUTION:When welding the butt part of an open pipe formed by bending a plate material by means of MIG welding, it is executed as mentioned below. That is to say, the end part of the upstream side in the weld advancing direction is welded under the welding condition which is set so that welding voltage is higher, and a welding current and a welding speed are smaller, than the welding condition of the center part of the open pipe. On the other hand, the end part of the weld advancing downstream side is welded under the welding condition which is set so that the welding voltage is lower, and the welding current and the welding speed are smaller, than the welding condition of the center part. According to this method, it is possible to prevent generation of a welding defect such as stubbing or humping, etc. in the end part of a pipe. |
