AC MIG与DC MIG焊接工艺及控制的分析

比较分析了DCEP P MIG焊与DCEN MIG焊的焊接现象，在此基础上，解释了研究开发AC P MIG焊的意义。AC P MIG焊克服了DCEP MIG焊时容易产生的磁偏吹现象，且比DCEP P MIG焊的焊丝熔化速度快、焊缝熔深浅。AC P MIG焊有多种电流模式，其交流电流负极性比率AC I EN％主要用于控制焊缝熔深，其交流电流正极性脉冲Ip主要用于控制熔滴过渡，最理想的是1周1脉1滴的熔滴过渡形式。根据有关的研究表明，在相同送丝速度的条件下，AC P MIG焊的焊缝熔深随AC I EN％增加而减小，焊缝表面光泽好，焊丝熔化金属热含量低等，这些特点最适宜用于焊接薄板。

The comparison of welding technology and control between AC MIG and DC MIG welding

On the basis of comparing and analyzing welding phenomenon of the DCEP P MIG welding and DCEN MIG welding, this paper explains the significance of researching and developing AC P MIG welding.The magnetic blow which is easy to generate in DCEP MIG welding is controlled in AC P MIG welding.Compared with DCEP P MIG welding,the welding wire melting rate is faster and the weld penetration isshallower.AC P MIG welding has varieties of current mode,the AC negative polarity rate AC I EN% is mainly used to control weld penetration , the AC positive polarity pulse I p is mainly used to control metal transfer. The most ideal form of metal transfer is a pulse with a droplet.The related research indicates that the weld penetration of AC P MIG welding is decreasing just as the AC I EN% is increasing in the situation same of wire feed rate.The characteristic of lustrous welding seam surface and low heat content of melting metal are available to weld thin sheet.