In my opinion no need to cut the cross section. For 20" you can just cut the weld (grinding or cuting disc) from center perpendicular to weld top surface (till the root ) for 2-3 inch circumferential length. Prepare the surface and etch with CuSO4 and if there is no copper colour indication menas there is no CS consumable used.
The chips (powder) can be collected from the lowest region tand sent for chemical analysis to prove that its have 18-8 chemistry.
And the opened void can be filled back as you weld some repair found in RT.
Thanks Mr. Prem Shankar,
I understand that the problem is more psychological ( because of client's previous bad experience-- of GTAW root welded by CS ) than technical.
I found a similar situation faced by others in another Engineering forum. The solution suggested were are destructive testing e.g chemical analyzing and etching (copper sulphate) the cross section of weld, PMI from inside ( root of field joints are in accessible from either ends- hence cutting required).
I'm exploring for any non destructive method which could do away with above and any similar experience of any group member.
I too have suggested him the mockup method, one as per WPS and other CS+SS one (The later piece was more magnetic than the correct one.) and demonstrating the soundness with in process documents as per QAP.
All his pipes are either sch 10S and 40S , size 2" to 20". For 10S and smaller dia, I suspect alloy dilution for any wrong welding and should be detected by PMI. For 40S and higher thk, I'm clueless.
Best Regards,
Rishi Raj Singh
From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of PREM SHANKARDUTT NAUTIYAL
Sent: Wednesday, January 20, 2010 7:41 AM
To: alouis1972@yahoo.co.in
Cc: materials-welding@googlegroups.com
Subject: Re: Re: [MW:4095] Magnetism in SS 304 & 321 after welding
Hi Suneel and Rishi
As your client is doubting that you might have used CS filler wire for root run and rest with SS filler wire, then to clear his doubts, weld one similar joint mockup in his presence with your WPS and show him that it is magnetic.
Also ensure that you are using SS wire brush for interpass cleaning.
In ASS min. 3 FN is required in weld deposit to prevent hot fissures.
Regards
Prem Nautiyal
On Tue, 19 Jan 2010 15:48:09 +0530 wrote
>Hi Sunnel,
In Austenitic stainless steel welding one of the susceptiablity problem is hot cracking. So avoid this problem, need some delta ferrite in welding ( which is maganetism).So consumable manufacturing is carried out based on this ferrite requirement. In my previous projects 3 to 8 FN requirementis given by client specification, For clear detail please refer AWS handbook - Volume 1.
>
Louis
Welding Engineer
Singapore
>--- On Fri, 15/1/10, suneel gore wrote:
>
>From: suneel gore
>Subject: Re: [MW:4050] Magnetism in SS 304 & 321 after welding
>To: materials-welding@googlegroups.com
>Date: Friday, 15 January, 2010, 10:17 AM
>
>
Sir
One of my customer also have faced similar problem , in case of welding SS 304 & 316 Plates , Tacking By E 316-16 Electrodes & welding by ER 316L FIller wires
The welded are attracts magnet , but same on filler , or plates or on stub ends it does not
Pl let us know
If is it the case of residual magnetisumdue to DC Welding ?
How it can be avoided?
Pl guide us
Regards
Suneel Gore
>
>--- On Thu, 14/1/10, Singh Rishi (TIPO - QA/QC) wrote:
>
>From: Singh Rishi (TIPO - QA/QC)
>Subject: [MW:4045] Magnetism in SS 304 & 321 after welding
>To: materials-welding@googlegroups.com
>Date: Thursday, 14 January, 2010, 6:25 PM
>
>
One of my friend is facing a problem, which I'm putting to the group as I'm not sure about the solution..
SS joints after welding has becoming magnetic ( Ferrite number is not a criteria for these joints) and hence attracted by magnet ( including Socket Joints )- mostly pipe to fitting joints , but his Client is doubting that they are becoming magnetic because it's root has been welded by CS filler wire- rest passes by SS filler wire.
This , he insists is done by welder to do the job faster and save purging- as per his past experience in some Gulf project.
There are some thousand of SS joints ( 304, 321 ) in his plant, which is ready.
What can be done, apart from PMI & Ferrite ( on which he doesn't have much faith as they show the reading of the Final pass ) , to convince him about the integrity of the joint without cutting/ drilling / damaging the joint.
Please share any literature which relates Magnetism to the Welding/ Ferrite percentage.
Welding Processes involved are GTAW (mandatory for all root welding ) and SMAW ( for above 8mm thk )
Thanks & Best Regards,
>
>Rishi Raj Singh
>
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