Abstract: Fume extraction torch was adopted to complete CO₂ gas shielded arc welding with flux-cored wire. Through recording fume diffusion pattern and change of welding current and welding voltage, analyzing droplet transition form by high-speed camera, comparing appearance of welds and revealing the weld defects by X-ray non-destructive testing technology, and comparing them with the situation without fume extraction, the performance of fume extraction torch under different fume extraction powers and torch inclination angles and its influence on welding process and welding quality are studied. The results show that welding fumes are effectively absorbed into fume extraction torch, the overall shape of the fumes is conical, and as the increase of fume extraction power, its stiffness increases and the effect of fume extraction is enhanced. The droplet transition form still appears as repelled globular transfer, and fume extraction only slightly increases the droplet transition frequency. Under different powers and given torch inclination angles, the welds are well formed and there are no defects in welds.

Key words: fume extraction torch, flux-cored wire, CO₂ gas shielded arc welding, fumes, droplet transition