MATHEMATICAL-MODEL OF ARC IN PULSED CURRENT GAS TUNGSTEN ARC-WELDING

A two-dimensional transient model is introduced to describe the heat t ransfer and fluid flow in pulsed gas tungsten are (GTA) welding. The c urrent continuity equation has been solved with the combined are plasm a-cathode system, independent of the assumption of the current density distribution on the cathode surface which was essential in previous s tudies of the are plasma. The temperature distribution in pulsed GTA w elding has been described, and the transition processes of temperature contours and current densities at the anode centre have been studied. Moreover, the effects of pulsed welding parameters on the dynamic pro cess of current density at the anode centre are studied using the deve loped model. The results have been compared with experimental data mea sured by the probe method.