Dynamic analysis of globular metal transfer in gas metal arc welding - a comparison of numerical and experimental results

A mathematical model to describe the globular transfer in gas metal arc welding is developed. This work is both theoretical and experimental. Using the volume-of-fluid (VOF) method, the fluid-flow and heat-transfer phenomena during the impingement of a droplet on a solid substrate, arc striking, the impingement of multiple droplets on the molten pool and finally the solidification after the arc extinguishes are dynamically studied. A He-Ne laser in conjunction with the shadow-graphing technique is used to observe the metal-transfer processes. Theoretical predictions and experimental results are shown to be in good agreement, suggesting that the theoretical treatment of the model is sound.