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Re: [MW:4050] Magnetism in SS 304 & 321 after welding

By Materials & Welding
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) <R.Singh@Panipat.ticb.com> wrote:

From: Singh Rishi (TIPO - QA/QC) <R.Singh@Panipat.ticb.com>
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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