Non-equilibrium modeling of arc plasmas in the gas-metal arc-welding process

In recent years, the thermal and chemical non-equilibrium properties of arc plasmas have been among the most critical topics in the modeling of welding arcs. Non-equilibrium phenomena can be observed in the near-electrode regions, where the characteristics of the arc are determined. Although non-equilibrium modeling should contribute to a deeper understanding of the gas-metal arc-welding (GMAW) process, no non-equilibrium model has been reported for GMAW processes, while several models have been reported for gas-tungsten arc-welding processes. In this study, we attempted to elucidate the non-equilibrium phenomena in the GMAW process. In addition, as a first step, we developed a non-equilibrium model of the arc plasma in the GMAW process. The influence of the iron vapor was successfully determined by our model. We then inferred that the concentration of iron vapor affects the number density of electrons and, consequently, the thermal equilibrium of the arc in the GMAW process.