| 摘要 |
PURPOSE:To form stably the beads in a welding start part and to prevent the generation of welding defects, by increasing gradually the feed rate of a wire up to the value in the state of regular welding, increasing sharply once the arc current then increasing the same gradually and further maintaining an arc voltage at the arc voltage value in the state of regular welding. CONSTITUTION:An arc is generated and after initial current I1 is conducted for a several seconds, a carriage is started as shown in the figure. The arc current is sharply increased once from I1 to I2 and is then gradually increased. At the same instant, the feed rate of a wire is gradually increased and the welding is so controlled that the arc current attains the prescribed I3 and the feed rate of the wire attains the prescribed value in the state of regular welding after a few seconds when the pool stabilizes. The set voltage is so set during this time that an adequate arc length is attained at the arc current I3 in the state of regular welding. As a result, the feeding of the wire at the rate meeting the size of the pool is fed and beads are stably formed without embedding the recess, whereby the generation of defects is prevented. |
