| 摘要 |
PURPOSE:To smooth a weld bead and to prevent welding defects by specifying the ratio of a start current value with respect to a stationary current value and the time elapsed until the current is changed over in the stage of changing over the current value at the start of a consumable electrode arc. CONSTITUTION:The ratio of a start current value with respect to a stationary current value and the time T elapsed until the current is changed over are determined respectively by 0.8>=Y>=(0.4/7)T+0.26, T>=2.5, more preferably (1/ 15)T+(7/15)>=Y>=(1/10)T+0.15. The weld start part is thus smoothed without building up from the stationary part, by which the fusion between the start part of the previous layer and the laminated part of the succeeding layer is made thorough and the generation of welding defects is prevented. A particularly remarkable effect is obtainable with the above-mentioned method in three o'clock welding by a narrow groove. |
