Determination of gas tungsten arc welding efficiencies

A combined experimental/computational technique for the estimation of gas tungsten arc welding (GTAW) efficiencies under quasi-steady conditions is presented. The instantaneous measurements of the weld pool length ahead of and behind the electrode are obtained from digitized free surface images, using a pulsed laser vision system. Measurements of the width and depth of the pool are obtained from weld sections using optical microscopy. Based on these measurements of the actual fusion boundary created by weldpool convection and other effects, a three-dimensional model outside the molten zone in the solid material is used to determine welding efficiency. Measurements and calculations are performed for a range of power inputs and torch speeds for both grooved and ungrooved, high-yield strength steel samples. Computed efficiencies are compared with those available in the literature.