3D simulation of stationary gas tungsten arc welding of L-shape, V-shape and open-corner joints

Abstract

This paper presents a three-dimensional simulation of stationary gas tungsten arc welding which studies the development of the arc and weld pool in three types of joints, namely L-shape, V-shape and open-corner. Temperature, heat flux, current density and gas shear stress are determined in the arc and are used as input to the workpiece to determine the heat, fluid flow and weld pool shape. Buoyancy and surface tension gradient which affect the pool shape are taken into consideration. It is observed that the current density, heat flux and gas shear distribution in the arc domain is the same in all the cases. The electromagnetic force is observed to be the same in L-shape and V-shape joints. In the case of the open-corner joint, some electromagnetic force is also observed on the bottom edge of the weld. The fluid flow and weld pool shape is found to be the same in the case of L-shape and V-shape joints which shows that the orientation of workpiece does not produce any gravity effect. Due to the sharp edge in the open-corner joint, the weld pool is observed to be shallow and wide. In all three cases, the molten metal flows from the sides and the weld pool is formed slightly upwards at the weld centre in the experimental results. This phenomenon is not considered in the numerical analysis and the weld pool depth near the weld centre is a little different from the experimental results; however, the remaining pool shapes are observed to be in good agreement.