Numerical Analysis On Keyhole Gas Tungsten Arc Welding

In this paper the K-TIG welding arc characteristics were studied by using numerical simulation technology. This mode of keyhole gas-tungsten arc welding is characterized by its dependence on Lorentz forces, as contrasted to recoil pressure in laser and electron beam processes, and a combination of recoil and stagnation pressure in the plasma arc process. Because of high temperature and strong arc interference in the K-TIG welding process, it is difficult to directly observe the behavior of the arc with the experiments. According to the magnetic fluid dynamics theory and the Maxwell equation, a three-dimensional mathematical model has been developed. In this paper a mathematical model was developed to study shielding gas within the K-TIG welding torch and welding arc by using numerical simulation technology. The physical model was built, based on K-TIG welding torch which Suzhou Ahand Ltd provided. Considering turbulence, the flow of shielding gas and the arc characteristics were simulated by the FLUENT software. The temperature field, the potential field, the arc pressure field and the plasma velocity field were simulated and calculated. The welding process parameters which include the welding current, shielding gas flow rate, arc length, tungsten shape and polarity,on the arc characteristics and arc surface pressure distribution. Flow field of the high-current arc welding, which were gotten and analyzed from the model. The results reflected the K-TIG welding arc characteristics. The results also showed that the factors of influence on K-TIG welding arc pressure include welding current, arc length and tungsten electrode angle. The results can be used to guide the K-TIG torch design, welding procedure.