Research On Physical Characteristics And Welding Process Of Twin-Electrode TIG Welding Method

The TIG welding method can produce high quality welds for its steady process and excellent weld bead appearance, however, one weakness of this method is that the deposition rate achieved is lower than for many other welding methods, because it can make big hollow and humping in a weld pool in high current and high speed region. In response to this need, this paper developed a high efficiency welding method—twin-electrode TIG welding method (T-TIG). This method can avoid big hollow and humping defection greatly, so it can obtain higher deposition rate without sacrificing the advantages of the original TIG welding method.First of all, system of researching on welding process and physical characteristics was constructed. In this system, the T-TIG torch is the most important part, and two electrodes which are insulated from each other are employed in the same torch, two power supplies for welding are connected to the two electrodes. Based on this system, the arc pressure, the static characteristic of arc and the temperature distribution of the welding work piece can be measured, the arc appearance and weld pool photos can be taken.The arc shape was taken by the CCD camera. It can be seen from the arc picture that the changing grade of arc cross section area becomes slow with the increase of the distance of two electrodes in the same current, and it is slower than the changing grade of conventional TIG arc. The arc pressure was measured by the WNK808b pressure difference sensor. It can be seen from the result that the arc pressure becomes low with the increase of the distance of the two electrodes, and it is lower than the conventional TIG arc pressure. The result of the measurement of the arc static characteristic shows that the arc voltage is lower than the conventional TIG in the same current of single electrode. The temperature was also measured, from the result we can see that the temperature of the same place on the work piece is lower compared to the conventional TIG in the same weld current and speed.Research on the welding process shows that the T-TIG method can avoid the hollow and humping defections effectively in high current and high speed region...