Numerical Simulation of GMAW Process from the Heat Source to the Weld Pool Formation

Abstract

Gas metal arc welding (GMAW) process is an indispensable technology in various industrial fields. The phenomena during the welding process such as the temperature history of the base metal strongly affect to the properties and performance of the weld joint. It is very important to predict and control the phenomena in the process, however, the phenomena is very complicated and not completely understood. In this study, numerical models of the heat source and the weld pool formation in GMAW process are constructed to visualize the phenomena and predict the welding results of the GMAW process. The heat source model includes the arc plasma and metal transfer phenomena. The temperature, velocity, pressure, and electromagnetic field in the arc plasma and the molten metal are calculated. Influence of the metal vapor from the surface of high-temperature metal is also considered. Input parameters of the heat source model are the welding condition such as the current and the shielding gas used in the experiment. The properties of the heat source such as the heat input distribution, arc pressure distribution and the temperature of the droplet are calculated by the heat source model. These properties are input to the weld pool model. The weld pool model calculates the flow and temperature fields in the weld pool and can predict the penetration shape and the temperature history in the weld joint. These models are applied to pulsed-MAG welding process, the numerical result of the penetration shape shows good agreement with experimental results.