Welder Performance Qualification GMAW Root/FCAW Fill & Cap ASME IX

[Dan K.]

Hi

I've just tested a welder on 0.5" thick plate for qualification to an approved WPS using a GMAW short circuit root & FCAW globular fill & cap. For the purposes of Form QW484a I've recorded the actual deposit thickness of the GMAW short circuit root measured @ 0.125" thick and the remaining 0.375" of fill was completed with FCAW- globular. The range qualified for GMAW per QW404.32 will be .14" (1.1t) and *normally* I would say that range qualified for the FCAW fill per QW452.1(b) would be .75" (2t).

However, after an interesting conversation with an associate yesterday, he contends that because ASME considers GMAW & FCAW to be the same process (QW355) that in actuality, the range qualified for FCAW can be "max to be welded" as the combined weld deposit thickness of 0.5" (.125" + .375") per QW452.1(b) would qualify for "max to be welded" (0.5" and over). It somewhat makes sense to me yet at the same time, it doesn't make sense to me.

I was wondering if anyone has any opinions on this? Any help would be much appreciated.

Thanks,

Dan

 

[david339933]

It is true that Sec. IX considers FCAW and GMAW to be the same, however the type of filler metal product form is an essential variable (QW-404.23) transfer mode for welder qualification is essential...short circuit vs globular (409.2). So no, you cannot qualify for "max to be welded".

 

[gtaw]

Section IX does not differentiate between GMAW or FCAW for the purpose of welder qualification. It does differentiate between the two processes with regards to the qualification of the WPS by including the filler metal product form as an essential variable.

Considering the WPSs for both GMAW and FCAW must be qualified separately, I would ask if the welder had a WPS for GMAW and a separate WPS for FCAW. In the absence of two WPSs I would expect a single WPS that includes both GMAW and FCAW with two supporting PQRs or one PQR that qualified the WPS for the GMAW root bead and FCAW for the remaining intermediate and cover layers. The question is asked because the welder must follow a qualified WPS when taking the performance test. If the welder didn't follow a qualified WPS while testing, the performance qualification test is void.



Best regards - Al

 

[Dan K.]

Thank you for your comments.

@david339933- so just so I can understand clearly, you're saying that because they are different modes of transfer, then fcaw-globular cannot be considered as part of the entire weld deposit thickness and needs to be considered by itself- so therefore the range qualified for fcaw will be 2t or 0.75"? If so, then I agree completely.

@gtaw- The test was conducted via an approved WPS with supporting PQR's with a gmaw s.c root & fcaw fill & cap. Deposit thickness ranges in the WPS are qualified as separate processes per asme ix. i.e. .14" for gmaw s.c. & .125" to 8" for fcaw.

I thank you both for your comments. My associate's belief that you could qualify the fcaw portion of the weld deposit to max based on it being "technically" the same process as the gmaw deposit (therefore you could combine the two) sounded plausible to me, yet didn't sit right.

Best regards,

Dan

 

[DVWE]

You've received some sound advice from david and gtaw.

Your "associate" sounds like the type of person that knows just enough about Section IX to be dangerous.

The devil is in the details; she also wears prada.

 

[gtaw]

For the purpose of welder performance qualification, GMAW-SC is limited to 1.1 x the thickness deposited. A change from pulse, spray, or globular to short circuiting is an essential variable for performance qualification. The 1.1 x the thickness is still the upper limit for the GMAW short circuiting transfer. The portion deposited with FCAW is separate from the portion deposited with GMAW short circuiting. The welder's range would be calculated based on the thickness deposited with each process. Had the GMAW portion been deposited with globular, pulse, or spray, the thickness range would be the sum thickness deposited by both GMAW and FCAW.

Best regards - Al

 

[Dan K.]

@ DVWE- yes, unfortunately this person is a cocksure engineer *and* a certified welding examiner.

@gtaw- Yes, bang on. I totally agree.

Thank you all again for taking the time to comment. When someone passionately argues their case, it starts to make one question themselves. Again, thank you for sharing your wisdom.

Dan