Short-circuiting mode GMAW receives special treatment because it has a history of welds being made with small, tight lack of fusion defects both at the side wall and between weld beads/layers. These are typically not detectable by RT but will open up when bend tested. These defects are the result of weldor technique. Understand that RT is an exemption/or permitted substitution for the required bend testing In this case the use of RT as an exemption/substitution is not extended to the GMAW-S process.
John
From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of ABHISHEK GHOSH
Sent: Monday, May 23, 2011 3:17 PM
To: materials-welding@googlegroups.com
Subject: [MW:11128] QW 304: Welders
Dear Experts,
As per ASME IX
QW-304 Welders :
Except for the special requirements of QW-380, each welder who welds under the rules of the Code shall have passed the mechanical and visual examinations prescribed
in QW-302.1 and QW-302.4 respectively. Alternatively, welders making a groove weld using SMAW, SAW, GTAW, PAW, and GMAW (except short-circuiting mode)
or a combination of these processes, may be qualified by radiographic examination,
WHY SHORT- CIRCUITING MODE IS EXCEPTIONAL ???
Regards.
Abhishek Ghosh
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ABHISHEK GHOSH
FAHAHEEL, KUWAIT
MOB: (00)965-60303798
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