Numerical simulation of droplet transfer with TiO₂flux column during flux cored arc welding by 3D smoothed particle hydrodynamics method

A molten metal droplet transfer processes were simulated by a numerical model using a three-dimensional smoothed particle hydrodynamics method in order to clarify the flux column formation mechanism at the tip of a wire during a flux cored arc welding process. This study focuses on the flux cored arc welding with TiO₂based wire.As a result, although the average droplet size obtained by the computation was larger than that by the experiment, the average length of the flux column obtained by the computation showed agreement with that by the experiment, which supports supported validity of this computational model. Moreover, the melting rate of the metal-pipe around flux was higher than flux. The flux column was formed at the tip of the wire. The simulations with different values of a specific heat and a thermal conductivity were performed to investigate the effect of the heat conduction in the wire on the flux column formation. The unmelted flux column was formed at the tip of the wire when the specific heat of the flux component was smaller and the thermal conductivity was higher than those of TiO₂. The result indicated that the heat conduction in flux played an important role in the flux column formation during flux cored arc welding.