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Re: Re: [MW:9542] Duplex stain less steel certificates misses nitrogen content


Hi

Nitrogen and oxygen upto 1 ppm can be determined more accurately by Leco TC-400 instrument using the inert gas fusion principle.

I had used this Leco - N2/O2 analyser in L&T, Powai.

Please refer attached file.

Regards

Prem Nautiyal

On Fri, 28 Jan 2011 13:00:18 +0530 wrote
>
Replied belowto yor queries.
>
Regards,
Ajay
>


From: murugesan jeyaraman
>To: materials-welding@googlegroups.com
>Sent: Fri, January 28, 2011 5:17:07 AM
>Subject: [MW:9532] Duplex stain less steel certificates misses nitrogen content
>
>
Dear all

I reviewed a Material certificate for Duplex SS, Plate A240 UNS S31803 and found Nitrogen content .08 – 0.2% as required by ASME sec II part A is not at all mentioned in the certificate. As vessels are fabricated and welded I issued a NCR to manufacturer.

Vessel manufacturer are going to ask Mill about this.

1) My question is how come a Mill certificate misses an essential element of composition required by the code? If the Mill comes with a reply that it is a clerical error to miss the Nitrogen content, and re-issue a certificate, can we accept it as genuine?
It may happen, sometimes the Mill misses to include such information. I believe, if the Mill re-issues the certificate afte correction, then you can accept it.

2) Is nitrogen content can be analysed by PMI or any other analyzing method in a lab test. Because the vessel fabricator say they are going to do lab test, for this.
The vessel manufacturer may have left over materials of same heat, which can be chemically tested at lab's for more perfect analysis or even by PMI as suggested by Mr. Karthik.

Please share your experiences and opinion about this.

Thanks

Murugesan
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For more options, visit this group's bolg at http://materials-welding.blogspot.com/
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The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.
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PREM S NAUTIYAL
CELL : 9769316004

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The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.

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