Alireza DoudmanTipi

Two forces play the main role on the drop detachment in gas metal arc welding process: the electromagnetic and gravitational forces. Since in an automatic pipeline system, the welding angle varies from 0° to 180° in each pass, the total force will vary, so the drop detaching will not remain invariable during the welding time. In the previous works Doodman Tipi (Int J Adv Manu Technol 50:137–147, 2010 [1]), Doodman Tipi (Int J Adv Manu Technol 50:149–161, 2010 [2]), the angle variation effects on the metal transfer was studied on both transfer modes (free flight and short circuit). In this paper, the effect of the input parameters on the drop detaching is studied. Also, a welding current pattern is presented in order to neutralize the effect of the angle variation around the pipe. Furthermore, suitable patterns for other parameters (arc voltage, travel speed, and electrode speed) are introduced to keep constant the molten electrode volume, heat input, voltage to current relation, and energy density. This would guarantee stabilization of the other welding specifications. Finally, several experimental and simulation examples illustrate to achieve the regular detachment using the presented method, and results are compared with the un-neutralized case.