Preliminary Research On Welding Of Single-Sided Series-Connected Double Tig Arcs Base On Single Power

In this paper a new form of welding heat source–single-sided seriesconnecteddouble TIG arcs based on single power is proposed. In order to findout the physical characteristics of the arc welding, a preliminary study on theworking mechanism, arc shape, arc static characteristics, heat characteristics,shaping law and other aspects of this type of arc welding is performed.Firstly, the welding experiment platform is established. It consists ofwelding power source, workbench, double gun holding device, motion controldevices and test equipment. In general, the positive and negative of arc weldingare made of the workpiece and the welding gun. In this study, two conventionalTIG welding torches are connected to the positive and negative of the powersupply, and the workpiece is not connected to the power supply. The currentflows from the torch 1 to the workpiece, then flows from the workpiece to torch2. It can create one arc between the torch 1 and the workpiece, and the otherbetween torch 2 and the workpiece. The two arcs are serial and it can form asingle power series single-sided double arc welding.The shape of the serial double-arc are observed and analyzed with a CCD.The serial double arc can be burned steadily, the arc contracts when the tungstenconnecting to the negative and the arc diverges when tungsten connecting to thepositive. The two arcs are mutually exclusive and the current and arc distancehave significant influence on the shape of this welding arc.The total voltage of the arc is about 25 volts by measuring the staticcharacteristic of serial double arc. It shows that the power of serial double-arc istwice of the power of traditional single-arc and it can make more heat input tothe workpiece with the same current.By the simulation of FEM, it shows that the penetration of the serialdouble-arc is bigger than that of the traditional single-arc.The influence of arc current and arc distance of the serial double-arc on thearc shape are investigated. Then the characteristics of welding formationbetween the serial double-arc and the traditional single-arc are compared. Thetests on low carbon steel and stainless steel workpieces show that the penetrationof the serial double-arc is deeper than that of the traditional single-arc.The results indicate that the serial double-arc is a new stable welding heatsource. It has a greater arc power and can be simply implemented. Therefore,this paper has some value of academic research and application.