De hydrogenition heat treatment for 5Cr material

[biju]

Our client spec. requires 5Cr material with thickness more than 10mm requires dehydrogenition heat treatmnet 

But the contractor has welded and immediately completed PWHT without going for DHT, Is that acceptable

[shanmuganathan .subbiah]

Dear 

It is not acceptable , Post heat shall be carried as per approved WPS

On Mon, Aug 3, 2015 at 8:01 AM, biju <biju...@gmail.com> wrote:

Our client spec. requires 5Cr material with thickness more than 10mm requires dehydrogenition heat treatmnet 

But the contractor has welded and immediately completed PWHT without going for DHT, Is that acceptable

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Regards

SHANMUGANATHAN SUBBIAH

AIB- Vincotte International & Partners LLC

PO.Box-420, PC -116

MAF, Sultanate of Oman

Tel: +968 24565771

Fax: +968 24565772

Mob: +968 92096714

Web:www.vincotte.com

[Kannayeram Gnanapandithan]

not required and it is not essential variable, since pwht is taken immediately after completion of weld is more than enough 

THANKS & BEST REGARDS,

KG.PANDITHAN, IWE,  AWS-CWI, CSWIP 3.1,

CONSULTANT-WELDING & QUALITY

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[james gerald]

 Not Required.  The reason for dehydrogenation treatment by raising the temperature to 250-300 degC is that hydrogen atoms are mobile and have more diffusivity which will drive the hydrogen out of the weldment depending on holding time 1-3 hours.

Not a good practice to avoid dehydrogenation treatment. In this case since PWHT was done immediately, it would have resulted in diffusion of hydrogen from the weldment and thus avoids delayed cracking.

Since this is a client specification violation, may be taking a RT after 48 hours may be a chance to convince the client.

 

Thanks & Regards

J.Gerald Jayakumar

0091-9344954677

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From: Kannayeram Gnanapandithan <kgpan...@gmail.com>
To: materials-welding <material...@googlegroups.com>
Sent: Monday, August 3, 2015 5:45 PM
Subject: Re: [MW:23258] De hydrogenition heat treatment for 5Cr material

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[Jay Poojary]

Hi Mr. Biju,

With due respect to all the experts comments, My question is how you qualified your procedure,  the same should be followed through out the project. Did you not considered the spec while establishing procedure.

I agree with the comment that it's a non essential variable. But WPS has to be revised.

Thanks & regards,

Jay Poojary
QA/QC Engineer,
OCLLC,  Nigeria

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[Zeghanu Gigi]

Dear Jay,

If the your  approved client spec.required dehydrogenation treatment,you have to respect it(mandatory!).Therefore WPS to be qualified including DHT.

Regards

GIGI ZEGHEANU

WELDING ENGINEER

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From: Jay Poojary <jayo...@gmail.com>
To: material...@googlegroups.com
Sent: Tuesday, 4 August 2015, 9:55
Subject: Re: [MW:23262] De hydrogenition heat treatment for 5Cr material

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[Shashank Vagal]

That's correct, I agree with Jay; a revision in WPS is required and thererafter to work as per it.

 

BR,

Shashank C Vagal 

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From: Jay Poojary <jayo...@gmail.com>
To: material...@googlegroups.com

Sent: Tuesday, 4 August 2015 12:25 PM
Subject: Re: [MW:23262] De hydrogenition heat treatment for 5Cr material

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