| 摘要 |
PURPOSE:To economize resources and to prevent the excessive increase in molten pools by supplying a shielding gas into a groove, oscillating a bended welding wire, and controlling the molten pool so as not to made into one pool by using low pulse currents. CONSTITUTION:A shielding gas is supplied through hollow grooves 4, 8 and a small hole 5 from a pipe for supplying of the shielding gas. On the other hand, a welding wire 9a is bended at a specified width and a specified pitch in the breadthwise direction of the groove by gears 11a, 11b for feeding and bending and forming. The curved wire is supplied through a nozzle 10 for feeding and conduction of electricity into the groove and is simultaneously oscillated in the thickness direction of materials 1, 2 together with the nozzle 10. Molten pools 13 are made shorter than the plate thickness by using a low pulse current method which changes the welding current in the thickness direction of the materials 1, 2 at every several seconds to conduct high current to both end parts of the plates and to conduct low current and high current alternately to the central part according to the plate thickness. Thus, the formation of one pool owing to an excessive increase in the molten pools is prevented and toughness is improved by the mutual refining effect of the weld layers. |
