磁致旋转射流过渡MAG焊接工艺分析

Welding process of magnetically induced rotating MAG

在设计一种工程实用性强、小型化的纵向磁场发生装置的基础上,将纵向磁场引入到98%Ar+2%O2保护的射流过渡MAG焊中,提出了一种稳定、可控、有规律的磁致旋转射流过渡MAG焊接工艺,并详细研究了励磁电流(磁场强度)对电弧形态及运动行为、焊丝熔化特性、熔滴过渡机制和焊缝成形的影响规律,同时指出了该工艺的不足之处—纵向磁场在抑制指状熔深的同时却形成了偏心焊缝。结果表明,外加纵向磁场后,MAG焊电弧、液锥和液流束都偏离焊丝轴线并高速旋转,熔滴过渡虽然偏离了焊丝轴线,但仍在电弧烁亮区内部进行;随着励磁电流的增大,电弧旋转角速度增加,可见弧长缩短,熔滴过渡速度加快,焊接电流减小,焊丝熔化系数提高。

On the basis of designing a longitudinal magnetic field generator with powerful engineering practicability and miniaturized structure,the longitudinal magnetic field is applied to streaming transfer MAG with the shielded gas of 98%Ar and 2% O2.Magnetically induced rotating MAG welding process is put forward.At the meantime,the influence on arc shape and moving behavior,wire melting character,drop transfer mechanics, and weld formation of exciting current is studied.The shortage of deflecting weld for this new welding process is pointed out.The result shows that under the effect of the outer longitudinal magnetic field,all of arc and molten cone and liquid metal jet deflect from the wire axis and rotate with high speed.The larger of the exciting current,the faster of arc rotating angular velocity,the shorter of arc length,the faster of drop transfer frequency,the lower of welding current and the larger of wire melting coefficient.