American Welding Society Forum
I have an important question about examining some slags trapped between two welds layers, which one of them executed by SMAW and other layer with SAW.
We have lots columns ,approximately 40 columns, that faced with this problem.
But the question is: which NDT method(s) do I should take or is (are) suitable to find the slag(s)?
It should said that we exactly do not know that where do slags trap in the weld metal.also the thickness of the plate are 30 mm.
I'll call for VT after SMAW and prior to SAW process
You may be able to detect it with a small diameter straight beam transducer. However, the depth must be deeper than the near field of the transducer or you can employ a delay line with the small diameter transducer.
Above OP seems the problem was discovered.....then why not using the same method of discovering the same problem
You know... I saw a crack on the center of the weld metal and when I ground the surface I understood that the slags trapped between weld layers.
In fact we can not use the destructive methods like that to find out where there are such trapped slags!
The surfaces of weld metal executed with SAW are concave and it is not possible to do that with normal prob!
What is the minimum size of UT prob? Do you know?
Unfortunately there is no QC to control that during fabrication process and when I randomly ground the surface of weld metal, about in 50% of weld metal, the slags of SMAW was discovered.
You need to involve a competent Level III to look into your problem and devise a reasonable approach to detect the presence of slag inclusions.
Good luck. Al
I will do and inform you as I find a proper approach.
Thanks dude ☺
Dudes, assuming that you confirmed the presence of slag, what will you do on those welds that had been completed?
Will you suggest to gouge out the SAW and reweld it? if you want to raise an issue, then you must be prepared for possible solution
that is acceptable to Engineer in charge. Will that be the reason of having crack? why don't you just ask for PT or MT to check if there are similar cracks?
If you are acting as Inspector, then why not review the test plan to find out if there is a hold point for visual inspection on presence of slag prior to SAW process. If nothing is stated, then you may consult the Engineer to find out if this stage is critical.
If not critical, then stop thinking of the best NDT method
Powered by mwForum 2.29.2 © 1999-2013 Markus Wichitill