Numerical simulation of arc plasma and molten metal behavior in gas metal arc welding process

In this study, to make clear the phenomena of the gas metal arc welding process more deeply, a simulation model including both the arc plasma and the metal transfer phenomena is constructed and influence of the arc current is numerically investigated. The simulation model used in this study considered the iron vapor generating from the high-temperature metal surface and surface deformation of the molten metal as the interaction between the arc plasma and the molten metal. The simulation result shows that the molten wire glows largely at the wire tip when the arc current is low. On the other hand, for the high arc current, small droplet detaches from the wire tip. These simulation results of the behavior of the molten metal show good agreement with the experimental results. The balance of the driving force acting on the molten metal at the wire tip is very important to determine the molten metal behavior, and when influence of the electromagnetic force becomes stronger than that of the surface tension, the transfer mode is changed. In addition, simulation and experiment are carried out using the same pulsed current, these results of the arc plasma and the molten metal show good agreement. Therefore, the simulation model constructed in this study can describe the phenomena depending on the arc current. These results show that there are possibilities to be able to predict the behavior in gas metal arc welding process and optimize the current profile by the simulation model for controlling the gas metal arc welding phenomena.