Droplet Transfer Phenomena in CO₂ Arc Welding by Flux-cored Wire

Abstract

The effects of welding parameters and wire compositions on the droplet transfer of CO₂ arc welding by flux-cored wire, have been examined by means of photograph by a high speed camera.
As the welding current and the argon content in CO₂ shielding gas are increased, the droplet transfer becomes more preferable; the average droplet diameter decreases and the transfer frequency increases.
The wire cross-sectional shape has almost no influence on the droplet transfer. Increase of flux percentage in wire is effective in the improvement of the droplet transfer.
As the increase of TiO₂, Fe-Si and Al₂O₃ or the decrease of CaF₂ content in flux, the droplets become smaller and transfer more frequently. The effect of iron powder and Fe-Mn content is almost none. These variations of droplet transfer can be mainly explained by the repulsive force of slag vaporization in the droplet suspended at the tip of the wire.