| 摘要 |
<P>PROBLEM TO BE SOLVED: To shorten tact time, to suppress a length of MIG arc to be long too much in arc start of plasma MIG welding. <P>SOLUTION: A welding wire is fed to advance, is made to contact with a base material, then is fed to retreat to be separated, thereby initial MIG arc is generated, the retreating feed is made to continue to make an arc length of the initial MIG arc long gradually to form a plasma atmosphere in a space between a plasma electrode and the base material, thereby plasma arc is generated. Feed rate of the retreating feed is set as a fast first retreating feed rate Fb1 until an arc length La of the initial MIG arc reaches a first basic distance Lt1, and is set as a low-velocity second retreating feed rate Fb2 after that. Thereby, since the retreating feed rate becomes fast when the arc length La is short, the tact time is shorten, and since the rate becomes low-velocity when being long, the arc length do not become too long. <P>COPYRIGHT: (C)2012,JPO&INPIT |
