Study On Cladding Welding Process Based On Tri-arc Double Electrode

This paper has studied on a new type of double electrode GMAW welding method:Tri-Arc DE welding method.This new kind of welding method has not only built two arcs between two wires and workpiece,but also the third arc between two wires.The introduction of the new arc makes it possible to adjust the ration of current through the wire and the workpiece,so that heat input to the workpiece can be controlled,which makes this new welding method has advantage of high deposition efficiency and low heat input.Firstly,by doing Tri-Arc single and double electrode plate surfacing comparative experiments,mataining the same welding speed and deposition rate of the wire.the result of single wire welding seam appeard undercut and humping,while the double electrode weld seam has a nice appearance with no defects.By comparing the back of the weld seam of the plate,the edge of double electrode weld pool was wider,which has improved wettability, making a better weld seam.Secondarily,In order to explore middle arc’s effect on the adjustment of the workpiece current,welding experments of a range of different middle arc welding current on the plate has been done,and waveform acquisition system was used to collect current of different eletrodes.The result showed that increasing the middle arc current can effectively reduce the workpiece current,while the weld penetration increased with middle arc current decreases,by this way,the weld penetration can be controlled.In the Tri-Arc DE welding processing experiments,by changing the middle arc current and power source frequency,the result indicates that welding splash rate increases with the middle arc current increases,and when the power source frequency changes from 100 Hz to 250 Hz,the welding splash rate increases with increasing frequency.By introducing the high-speed camera and waveform acquisition system,arc shape and droplet transfer behavior during welding process has been acquired and explored,according to analysis, the mechanism of the influence how the middle arc current and power source frequency affect the welding splash was obtained.Finally,the investigation has been carried aiming at explore different processing parameter of Tri-Arc DE flux-cored plate cladding experiments.By measuring thehardness of cladding layer and microstructure analyzed,the results show that the weld penetration depth was smaller in higher middle arc current,and the base material has a higher dilution rate.The second phase distributed uniformly, which enhanced the performance of cladding layer.