Numerical simulation of GMAW processes including effects of metal vapour and sheath mechanisms at the electrodes

M. Hertel¹ - M. Schnick¹ - U. Füssel¹ - S. Gorchakov² - D. Uhrlandt²

¹ Technische Universität Dresden, Institute of Surface and Manufacturing Technology, Joining Technology and Assembly, D-01062, Dresden, Germany
² Leibniz Institute for Plasma Science and Technology (INP Greifswald), Felix-Hausdorff-Str.2, D-17489, Greifswald, Germany

Abstract
Gas metal arc welding (GMAW) is a common industrial process used to join a wide variety of materials. In the past, numerical models of GMAW-arcs with different complexity had been developed. However, deficits of GMAW-arc models result mainly due to the axis-symmetric formulation of the conservation equations and due to the simplified description of the effects in the sheath layers. Therefore, an additional three-dimensional approach is used, including effects of the movement of the welding torch over the workpiece. Furthermore, a new approach for modelling the effects of the sheath layer is presented. Therefore, the MHD-arc model is combined with a 2T-sheath model for the non-equilibrium layers near the electrodes. As a first step, the sheath model is implemented on the cathode sheath layer at the workpiece. The model is used exemplary for a metal-inert-gas welding arc with a ferrous wire. Figs 6, Refs 17.