Effects of shielding gas on metal transfer and arc shape of rutile type flux cored wire

Metal transfer mode and arc shape of rutile type flux cored wire with different shielding gas of 100% CO₂ and 80% Ar+20% CO₂ have been researched by high speed camera and analysator hannover. The results show that the repel transfer characteristics are low, medium and high parameters in the case of 100% CO₂. Droplet size decreases and transfer frequency increases with the increase of arc voltage and welding current, Globular transfer are found at higher parameters and corresponding waveforms are serrated; In 80% Ar+20% CO₂ globular transfer are considered on the main transfer mode. Projected spray transfer are observed at higher parameters, which bring near linear waveform. Slag column are found only at the early stage of droplet formation and growth for 100% CO₂, but which appear during metal transfer for 80% Ar+20% CO₂ that act as orientation and stable on the metal transfer. This is related to different arc shape that results in different arc heating effect on droplet and slag column.