Numerical analysis modeling of temperature field in swing-arc narrow gap GMA welding with additional wire

This study develops a heat source model for swing-arc narrow gap gas metal arc welding (SA–NG–GMAW) based on macrothermal transfer theory and geometric feature of weld cross-section after considering the influence of arc swing, a geometric feature of welded joint, movement of the additional wire, and weld surface shape on the arc heat flux distribution. The transient temperature profile and thermal cycle curve in SA–NG–GMAW were calculated using ANSYS software, and their distribution features were analyzed. The results show that the established heat source model can accurately reflect the moving path of the swing-arc and its thermal action feature. Furthermore, the calculated geometry and size of the weld cross-section and thermal cycles of temperature measurement characteristic point agree well with the experimental data, which validates the accuracy of the developed model. The thermal cycles at the weld toe have five peaks, with an interval of about one shaking cycle between two adjacent peaks. Without the additional wire, there is a noticeable “double peak” feature at the bottom of the cross-section of the weld, whereas the “double peak” feature is diminished with additional wire. The additional wire does not significantly increase the width of the heat-affected zone under the condition of effectively improving the welding efficiency.