| 摘要 |
PURPOSE:To improve welded conditions between the copper member and iron member by gradually reducing the main welding current of arc welding when welding is half done, and after one rotation around the circumference by reducing the main welding current abruptly, then after it is maintained at a constant value just prior to the termination of welding finally by cutting it off. CONSTITUTION:When the periphery of an positive electrode cylinder 11 made of cylindrical copper member and that of a pole piece 13 which is a ring-shaped iron member and that of the endplate 14 of a container are to be welded, during the period form the starting of welding along the circumference the end of welding after one rotation, in the main welding period, at first the welding is carried out while the main welding current is maintained at the value of the initial welding current, thereafter, the value of the current is reduced gradually. After the main welding period, during the slowdown period, the value of the welding current is abruptly reduced, and then during crater treating period, the value of the welding current is maintained at a constant value. As soon as the crater treating period ends, the current is cut off. According to this method, excessive temperature rise of the welded part and excessive melting of the welded part is controlled during the second half of the main welding period. Furthermore, the depth of fusion and the width of the fusion at the early and last stages of welding are made uniform. Thus good welded conditions all around the circumference is obtained. |
