变极性脉冲MIG焊的控制

研究变极性脉冲MIC焊的主要目的是控制形成浅焯缝，高效焊接铝合金薄板变极性脉冲MIG蚌的控制系统由逆史控制系统和单片机控制系统构成。控制系统协调控制电弧极性、电弧稳定性、焊丝熔化及熔滴过渡、电弧电压等焊接参数，获得稳定的焊接过程。变极性脉冲MIG焊在电弧EP极性时，利用脉冲电流熔化焊丝、形成熔滴过渡，电弧EN极性时电弧沿焊丝端上爬，EN极性电孤促进焊丝熔化、减小电弧对熔池的加热作用，减小焊缝熔深，焊接薄板时其有独特优势。

Control of variable polarity pulse MIG welding

The main purpose of studing on variable polarity MIG welding is to control the forming of shallow seam and to weld Aluminum alloy thin sheet efficiently.The control system of variable polarity MIG welding was composed of inverter control system and SCM control system,which parameters,such as arc polarity,stability of arc,melting of welding wire,metal transfer,arc voltage were controlled by control system coordinately to implement the stable welding procedure.When in EP polarity arc,the variable polarity MIG welding made use of pulse current to melt welding wire and form metal transfer.But as in EN polarity arc,arc would run-up along the welding wire,EN polarity arc would accelerate the melting of welding wire,reduce the arc's heating influence on molten pool,and reduce seam's penetration,which was of special advantage to weld thin sheet.