Effects of Welding Conditions on Molten Drop Geometry in Arc Welding

Abstract

The precise geometry of the molten drop attached to the electrode has substantial influence on the metal transfer. The geometry of the drop is a function of various parameters including the welding current and voltage, composition of shielding gas, electrode extension and material properties of the electrode. A new approach is proposed to enable an improved description of the molten drop drop in equilibrium. Among various forces which influence the profile of the static pendant drop, the surface tension, gravity and electromagnetic forces are considered to formulate the energy of the molten drop system. The present formulation leads to a numerical scheme, which is based on discretizing the volume of the drop with appropriate slabs. By minimizing the energy of the molten drop system, the proper shape of the drop is calculated. Explicit effects of a number of welding conditions parameters are evaluated. These include the welding current, molten drop volume and arc covered area. The model predictions are shown to be in satisfactory agreement with the available experimental data. These comparison exercises give credence to the robustness and accuracy of the present methodology.