It is not clear whether you are using GTAW or GMAW processes as you have mentioned of both in your post.
Towards GTAW, we do not get any defects when used in 6G position on CS, SS,AS etc., if done properly. It could be either GTAW for root to cap passes (or) GTAW for root & filler and cap by SMAW /GMAW / FCAW.
Towards, GMAW process on pipes, in order to get x-ray quality welds we prefer GTAW or SMAW for (mostly GTAW) for root pass and balance filler /cap passes by GMAW.
In all the cases minor defects like Lack of Penetration (LP), Lack of Fusion (LF) Excessive Penetration (EP), undercut (U/C) Incomplete Penetration or Fusion (IP/IF). Porosity, slag lines etc., are common defects.
Tungsten inclusion is an additional defect we normally see in GTAW.
Wire stubbing ( un-melted wire pieces) in the root is another defect we see in GMAW if used directly in the root.
Trust above details are clear.
Sridhar.
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Defects in GMAW
Re: Defects in GMAW
