Study On The Mechanism Of Alternating Double Arc Welding

The traditional single heat source welding technology is mature,but there are inherent shortcomings: its welding current and the amount of deposited metal are approximately linear,the two can not be decoupled,and increasing the amount of deposited metal means increasing the welding current,which will increase the welding heat input.In many cases,the workpiece has clear requirements for welding heat input,so there is a clear limit on welding current,which makes the control range of weld forming coefficient very limited.Moreover,the conventional single heat source welding process can not adjust the distribution of heat input,so it can not reduce the temperature gradient at the welding toe,and it is easy to produce welding defects when welding at high speed,which hinders the improvement of welding efficiency.the alternating double arc welding process studied in this paper,the main arc and the auxiliary arc can be alternately combined.with the switching of the power supply switch tube,the energy intensity of the auxiliary arc can be adjusted by changing the switching ratio,and the amount of deposited metal and the welding heat input can be controlled separately.In this paper,the existing alternating welding test platform is optimized,a reasonable welding waveform control program is designed,the dynamic response of the power supply is improved by engineering experience method,and the core control board of the power supply is replaced,and the wiring of the power supply circuit is make the welding process of the welding system more stable and reliable.In addition,a double-gun clamping mechanism is designed and built to realize the precise adjustment of the space position and posture of the composite welding torch.Double TIG arc welding test was designed to study the arc morphology of two electrodes in different position and attitude parameters,explain the conduction mechanism under different arc morphology and summarize the arc morphology of two electrodes under different space position and attitude of two electrodes.TIG-MIG alternating double arc composite welding test is designed,the behavior of main arc and auxiliary arc during alternating double arc welding is photographed by high speed camera technology TIG-MIG explain the mechanism of auxiliary arc dynamic switching.Based on the stability of arc switching,the effect of auxiliary arc on the transition of MIG droplet is studied.The effects of wire pole spacing,auxiliaryarc current and conduction time on droplet transition stability were investigated by welding test.The weld seam of single wire MIG welding,single tube conduction TIG-MIG composite welding and alternating conduction TIG-MIG composite welding are compared and analyzed to find out the weld forming characteristics under different welding methods.The welding seam of single wire MIG welding and TIG-MIG alternating composite welding is compared to improve welding speed,and the effect of alternating double arc welding process on improving weld quality is verified.the composite welding process method studied in this paper can not only decouple the amount of deposited metal and the welding heat input,but also adjust the distribution of welding heat input,reduce the temperature gradient of the base metal,and provide a new method for efficient welding.