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[MW:2087] Re: No Defect Revealed procedure ?

By Materials & Welding
Hi Prem,
After repair you are supposed to perform the same NDT method first (here UT will tell you the depth etc more correctly than RT can, if the slag is not removed effectively. If it is removed and the repair is effective, that also, will be revelaed by UT) and then you should go for an additional NDT method as a counter check.
Any other comments are welcome.
Rgds,
Shashank Vagal

--- On Sat, 2/5/09, PREM SHANKARDUTT NAUTIYAL <prem_nautiyal@rediffmail.com> wrote:

From: PREM SHANKARDUTT NAUTIYAL <prem_nautiyal@rediffmail.com>
Subject: [MW:2080] No Defect Revealed procedure ?
To: materials-welding@googlegroups.com
Date: Saturday, 2 May, 2009, 8:47 PM

Hi Friends

Can anyone guide me about how to carry out NDR (No defect Revealed)procedure for Repair Welding.

The matter is:

We have a circ. seam of two shells ,1m OD,35mm thick.Material Alloy Steel (marine steel).Double V butt joint welded by SMAW.
We landed up in a slag inclusion after RT.
Now by UT we found out the depth of slag i.e 10mm from top and length 100mm. So we grinded upto a depth of 14mm from top. Then we conducted RT for ensuring No Defect was Revealed or Present.
But surprisingly the RT film was just dark with lot of density variations and we could not confirm whether the defect (slag) was removed or not as it was difficult to interpret the radiograph.

Now can anyone help me out : How do we ensure by Radiography that the defect is removed after grinding. i.e how do we conduct Radiography of such partially grinded areas.

Also the material can be repaired only twice, hence i want to confirm that the slag at depth of 10mm is completely removed before welding.

Are there any other NDT method for doing NDR for repairing welds ?

Regards

Prem S Nautiyal
Cell:9820313278


PREM S NAUTIYAL

CELL : 9820313278

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