Why Cathodic cleaning or sputtering is ineffective in SMAW / GMAW?

Nivas Ramachandiran @Nivas_Ramachandiran

12 December 2016 1 9K Report

Cathodic cleaning which takes place in GTAW with AC polarity helps in welding reactive metals as during DCEN cycle the surface oxide layer gets cleaned and during DCEP cycle welding takes place. Why cant we achieve the same in other arc welding processes?

Pankaj Biswas

Generally, in SMAW / GMAW consumable electrode is used. In DCEN, the electron flow from electrode to base metal. Here Cathodic cleaning is there but that is not much effective due to the formation of molten droplet and detachment from electrode.

But in GTAW, generally electrode is non-consumable.

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