This study conducted three-dimensional transient numerical simulations for second pass gas metal arc welding on V-groove in various welding positions. To obtain arc models such as arc heat flux, electromagnetic force and, arc pressure, this study adopted the Abel inversion method and the resultant asymmetric arc models can be formed. Due to the different gravity effect, it is possible to obtain the different molten pool flow patterns, solidification times, temperature distributions and bead shapes along the welding positions by numerical simulations. The formation process of convex and concave weld bead has been analyzed in detail for different welding positions. The simulation results of the fusion zone were compared with the experimental ones; therefore, the various models used in this paper can be validated. (C) 2015 Elsevier Ltd. All rights reserved.