摘要
A hot-wire gas metal arc welding （GMAIV） method using a TIG arc to preheat the wire was proposed and a corresponding experimental system was developed. The images of molten metal droplets in GMA W with thick-wire diameter of 3.2 mm were captured by a high-speed camera, and the influence of the wire temperature on metal transfer was analyzed by measurements of droplet radius and transfer frequency. Two metal transfer modes were mentioned in this paper： the short- circuit transfer and the globular transfer mode. The results demonstrate that the wire temperature significantly impacts the metal transfer mode, droplet size and transfer rate at a certain welding current range. And with the increasing wire temperature, the change of metal transfer mode was observed. By increasing the temperature of the welding wire, the droplet size decreases and the droplet transfer frequency increases accordingly. In addition, it is important that the drop spray mode, which hardly occurs in GMAW with steel wire, was obtained by means of increasing the wire temperature.
A hot-wire gas metal arc welding （GMAIV） method using a TIG arc to preheat the wire was proposed and a corresponding experimental system was developed. The images of molten metal droplets in GMA W with thick-wire diameter of 3.2 mm were captured by a high-speed camera, and the influence of the wire temperature on metal transfer was analyzed by measurements of droplet radius and transfer frequency. Two metal transfer modes were mentioned in this paper： the short- circuit transfer and the globular transfer mode. The results demonstrate that the wire temperature significantly impacts the metal transfer mode, droplet size and transfer rate at a certain welding current range. And with the increasing wire temperature, the change of metal transfer mode was observed. By increasing the temperature of the welding wire, the droplet size decreases and the droplet transfer frequency increases accordingly. In addition, it is important that the drop spray mode, which hardly occurs in GMAW with steel wire, was obtained by means of increasing the wire temperature.
