There are prequalified WPS'sen for GTAW. Lots of welding machine and filler metal fabricators (Kemppi, ESAB, ...) offer those according to EN ISO 15612.

It's tough to provide a response when the applicable code or standard isn't provided in the post.

GTAW isn't prequalified per AWS D1.1 Structural Welding Code/Steel because it isn't typically used for joining structural steel connections. While GTAW is often used when welding thinner material, they are not typically used for structural steel framing for buildings, thus D1.1 is not applicable to materials less than 1/8-inch unless approved by the Engineer. There are provisions in the code that allows the Engineer to approve the use of a SWPS. The SWPSs can be purchased from AWS and then you would have a WPS for GTAW for carbon and high strength low alloy steel.

Best regards - Al

Well said gtaw.

a star for you gtaw!

luis

It's been a while since I have been in welding, that said I was heavy into commercial, aerospace and aircraft welded assemblies, It was mostly prime internal and government specifications and requirements.
and it was the requirements for a welding engineer to to provide the factory with setup procedure and a weld schedule that pass the requirements (Blue print & specifications). including the NDT and destructive testing.

No additional information from the person posting the question? I guess it isn't that important.

Best regards - Al

Quote (Engtiuser2)

However, it is not part of the pre-qualified weld for steel.

Not true for CSA W59.

Thanks everyone. We still use GTAW for 1/8" and 1/4 sheet and the weld is just unmatched by MIG. It has good penetration and low distortion. In my opinion, it should still worth to be part of pre-qualified weld.

GTAW "has good penetration and low distortion."
I'm not sure that is generically correct, especially the distortion part.

If MIG has proven lacking in "penetration" I'd suspect the weld prep and parameters are incorrect. Is it possible your team's weld settings were resulting in "short circuit" MIG ?

Manual GTAW is worst among the common welding processes for distortion.
When it comes to penetration in general, it is impossible to generalize.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

TIG was once upon time the goto process for aircraft & aerospace, was was done for years. don't know about now.
it was used for low distortion, and good penetration, and minimal weld defects. I am sure there are pro's and cons between
mig & tig.

edit : TIG had to pass stringent NDT requirements with no defects, or indications.