QW-462.2 .............. Side Bend Specimens

[Fizza453]

We welded a test coupon 41 mm thick to qualify three welders by mechanical testing, the finished transverse guided side bend specimens have dimensions 37 mm x 250 mm x 10 mm, the thickness has been reduced from 41 mm to 37 mm, is it acceptable?

Opening para. QW-462 says all dimensions are approximate unless tolerances, minimum or maximum is specified, so from this sentence I conclude that 37 mm instead of 41 mm is acceptable, please correct me if I am on the wrong way.


Nasir
Welding Engineer
DESCON ENGINEERING LIMITED
PAKISTAN

 

[gtaw]

You removed metal from the face and possibly the root surfaces of the completed weld. What was the purpose of removing 5 mm from the surfaces? Was it because the weld had excessive undercut and would not pass the test if left intact. Was it to remove portions of the welded groove that was underfilled? Did you remove metal from the root surface to remove incomplete fusion or incomplete joint penetration?

It is customary to remove any face or root reinforcement to provide a specimen that is flush with the surface of the base metal. It is not customary to remove metal for the purpose of removing weld irregularities and defects.

In my opinion it is not reasonable or acceptable to remove 2 1/2 mm (nearly 1/8 inch) from either the face or the root.

Best regards - Al

 

[Fizza453]

we did remove metal of approx 4 mm from root side to attain parallel surfaces, the test coupon was distorted a little

Nasir
Welding Engineer
DESCON ENGINEERING LIMITED
PAKISTAN

 

[metengr]

It is permissible to remove material to provide parallel surfaces, if there is distortion. This is why the wording is provided in Section IX.

 

[gtaw]

These are side bend specimens. They do not have to be parallel in the same sense as a reduced section tensile test specimen. Even in the case of a reduced section tensile test it is desirable to retain a portion of the root bead when machining the samples to be parallel.

There should be no need to remove base metal from the face or the root unless there is an attempt to remove surface breaking defects. Since this is a welder performance test, issues such as incomplete joint penetration, incomplete fusion, etc. should be cause to reject the test coupon.

The visual criterion provided by Section IX is sparse to say the least. I apply the visual criteria of the applicable construction code, i.e., Section I, B31.3 Normal Fluid Service, etc. when qualifying welders. There is little sense in sending a welder to the production floor or to the construction site if he or she cannot produce a weld that meets the applicable acceptance criteria. After all, isn't the purpose of performance qualification to have the welders demonstrate they possess the minimum skills necessary to meet the requisite code requirements?


Best regards - Al

 

[metengr]

gtaw;
Pure speculation on your comment above.

 

[gtaw]

Not to appear to be argumentative, but it would be perfectly acceptable to remove 5, 10 or 15 mm from the face and root surfaces of the welder's test coupon? They started with a 41 mm (1 5/8 inch thick) and reduced it to 37 mm (1 7/16 inch), that would cause me to wonder why.

Back to my comments; if there was a need to remove as much material as noted in this post and it was to remove surface discontinuities I would red flag it.

Once again, these were side bends. There should be no need to machine the face and root surfaces to provide parallel surfaces in that particular plane. The critical dimension is the thickness of the side bend which should be about 9.5 mm (3/8 inch). That dimension must be uniform and parallel so the side bend can be performed. Angular distortion of the plates shouldn't be an issue for the side bend.

ASME; always, sometimes, maybe, or except. They don't blow up that often.

Best regards - Al

 

[Fizza453]

we did not attempt to hide any objectionable defects that may cause side bend failure, we first performed visual examination , off course, before we obtain parallel surfaces.
Opening paragraph QW-462 also says that all dimensions of test specimens are approx.

Nasir
Welding Engineer
DESCON ENGINEERING LIMITED
PAKISTAN