Study On High Speed Breezing Process Of Arcing-wire PAW

In order to meet the demand of automotive lightweight,development of efficient welding,the advantages of sheet materials such as DC06 steel in the manufacturing of automobile body have become more and more prominent,most of the automotive structural parts are lap joints.Therefore,lap joint welding of sheet materials with high quality becomes hotspot in automobile industry.Due to the stability of the traditional arc brazing,high welding efficiency and many other advantages,arc brazing has become one of the commonly used technologies of lap welding.But in the traditional arc brazing process,due to the mutual coupling among heat,mechanics and mass transfer,the thermal input of the work-piece is difficult to control,thus,the conventional arc welding techniques are not suitable for welding sheet materials at high speeds.In this paper,for high-speed welding of thin plate materials in automobile,it is necessary to ensure the stability of the arc,the sufficiently filling of the weld metal,and the low heat input and the small welding distortion.Decoupling control of heat and mass,a new welding technology of "arcing-wire PAW welding process" is proposed.The novel welding process can freely provide the needed deposition and heat input as desired by different applications.The two arcs are coupled and interacted as that many parameters can affect the stability of the coupled arc,thereby affect the quality of automobile welds.The novel welding process are at least two arcs coupled with each other.This study tries to find the mechanism of the coupled arcs for arcing wire PAW,in the research of the behaviors of the arcs,the experimental system should record all the signals of the arcs for the welding processes: PAW as the main arc is supplied by a plasma power source and side arc is supplied by a TIG/MIG power source,the high speed camera,DAQ,voltage sensors,and current sensors can be realized the acquisition in synchronous experiment system.The effects of welding parameters on the arc behavior and droplet transfer behavior were investigated when the side arc was in constant voltage mode and constant current mode respectively.The experimental results show that the droplet transfer is stable and no spatter,with the increasing of side arc current,the droplet transfer rate increases in the constant current(CC)mode,however,when wire feeding speed is too high,the welding wire is not melted and through the plasma arc.When the side arc current and wire feeding speed change,the side arc voltage and plasma arc voltage are fluctuation in regular,the plasma voltage decreases when the side arc voltage rises,however,the side arcs current and plasma current are both in stable.When the side arc is in constant voltage(CV)mode,the side arc voltage increases,the droplet transition frequency increases gradually.The droplet transition from large droplet to contact transition is stable.With the increaseing of wire feeding speed,the melting speed,droplet size and transition frequency also increase.But when the wire feeding speed is too high,it will cause the wire feeding speed is faster than the wire melting speed,which will make it too late to melt through the main arc.With the increaseing of the PAW current,the PA force promotes the droplet transfer,but when the PA voltage increases,the side arc is affected.The macroscopically joint,element diffusion behavior and mechanical properties of weld formation under different welding parameters are analyzed in this research.The present welding speed of the welding process is further verified,because the coupled arc is elongated into an elliptical heat source in the welding direction to ensure the full heat preservation and wetting spreading of the weld pool in high speed welding,the stable and reliable high-speed welding speed up to 2 m / min is realized.