Dynamic Simulation of Metal Transfer in GMAW, Part 1: Globular and Spray Transfer Modes

摘要

The dynamic characteristics of the globular and spray metal transfer modes are simulated by adopting the Volume of Fluid (VOF) method. The electromagnetic force due to the welding current is included in the formulation of the VOF algorithm. The effect of the welding arc is considered under the assumptions of a uniform and linear current density on the pendant drop surface. The free surface profiles, pressure and velocity distributions within the drop are calculated numerically. It is found that axial flow and radial pinch force promote drop detachment, and the taper of the elongated molten drop in the spray mode is maintained by the electromagnetic force. The current density distribution on the drop surface has significant effects on the molten drop profile, detaching drop volume and taper formation at the molten tip. Predicted results are in reasonably good agreement with the experimental data.