Characteristic of hyperbaric GMAW metal transfer at 1-12 bar argon environment

The metal transfer behavior in hyperbaric GMAW process was investigated by using a high speed camera system with infrared laser as backlight. The metal transfer mode at 1-12bar argon environment shows different characteristics. Three kinds were observed: large droplet repelled transfer, projected repelled transfer and hyperbaric streaming transfer. Large droplet repelled transfer occurs mostly in the welding process with low feeding speed and relatively low welding voltage. Projected repelled transfer appears at middle feeding speed and high ambient pressure. Transfer tracks of former two modes deviate from the axial direction of welding wire. The spatter is produced more frequently in the projected repelled transfer mode. Hyperbaric streaming transfer is found meanly at high feeding speed and relatively high voltage. Because of its stability reflected from metal transfer process, hyperbaric GMAW process with hyperbaric streaming transfer mode should be employed preferentially.