Hi
1) SS contains more than 11% Cr which has higher affinity to oxygen and to get oxidised and form Chromium oxide as compared to CS. Hence while welding SS materials it is always essential to purge with Ar for the root & hot pass to avoid oxidation at root.Argon purging at the root drives out all the entrapped Oxygen thus creating an inert atmosphere.
2) Now when you weld CS,generally no Ar purging is required.
However if you are fabricating a Nuclear Class 1 component, Ar purging is required for TIG and is an essential variable in the WPS even for CS welding.
You will definately find a difference in the root when you purge with Argon -- A good uniform penetration, free of oxidation.
Thus if you need a quality weld there is no harm in Argon purging for CS material . of course the cost will go up !
Regards
Prem Nautiyal
Godrej,Mumbai
On Tue, 16 Jun 2009 17:37:09 +0530 wrote
>OK,why SS is more suseptable than CS to get oxidised?
>
>--- On Tue, 16/6/09, Antonio Ruscitto wrote:
>
>
>From: Antonio Ruscitto
>Subject: [MW:2447] requirement of purging in CS/SS pipes
>To: materials-welding@googlegroups.com
>Date: Tuesday, 16 June, 2009, 5:02 PM
>
>
>
>Hi:
>I think that is for the same reason. Ive qualificated a Welding Procedure Specification with ASTM 106 G B, with gas purging Ar inert gas. Because that reason
>
>Regards
>Antonio
>
>>>> Sukamal Naskar 11/06/2009 08:36 pm >>>
>
>
>For Stainless steel we do purging ( Inert gas like Argon ) to avoid the oxidation at the root. Stainless steel is more susseptable to oxidation than carbon steel.
>for carbon steel root is not so much suseptable to oxidation , hence we don't use purging gas like Argon.
>
>Regards,
>
>
>On 6/11/09, prashant pansare wrote:
>
>
>
>
>
>1) Why purging reqd.while welding with E316 / 316L for SS pipes?
>2) Why purging not reqd.while welding with ER 70-S for CS pipes?
>Pl. reply.
>
>
>Bring your gang together. Do your thing. Find your favourite Yahoo! Group.
>
>
>
>--
>Sukamal Naskar
>Malaysia
>
>
>
>*********************************************************************
>IMPORTANTE!
>Para evitar accidentes por inhalacin de monxido de carbono:
>- Mantenga los ambientes ventilados en forma permanente.
>- Revise que la llama sea color azul y uniforme.
>- Instale y haga revisar peridicamente sus artefactos slo a travs de gasistas matriculados.
>Recuerde que los artefactos a gas pueden emitir Monxido de Carbono: un gas altamente txico e imperceptible.
>Ms consejos en http://www.metrogas.com.ar
>*********************************************************************
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>This message is private and confidential and it is only intended for the addressee named above. If you have received this message and it is not addressed to you, please advise us immediately at error-mail@metrogas.com.ar and kindly remove it from your system. The use or disclosure of its contents may be regarded as an offense. Do not copy, reproduce or disclose them, either partially or fully. Opinions are the exclusive responsibility of the author and do not represent the opinion of MetroGAS S.A. - Thank you.
>:: http://www.metrogas.com.ar
>
>
>
>
>
> Explore and discover exciting holidays and getaways with Yahoo! India Travel http://in.travel.yahoo.com/
>>
>
PREM S NAUTIYAL
CELL : 9820313278
1) SS contains more than 11% Cr which has higher affinity to oxygen and to get oxidised and form Chromium oxide as compared to CS. Hence while welding SS materials it is always essential to purge with Ar for the root & hot pass to avoid oxidation at root.Argon purging at the root drives out all the entrapped Oxygen thus creating an inert atmosphere.
2) Now when you weld CS,generally no Ar purging is required.
However if you are fabricating a Nuclear Class 1 component, Ar purging is required for TIG and is an essential variable in the WPS even for CS welding.
You will definately find a difference in the root when you purge with Argon -- A good uniform penetration, free of oxidation.
Thus if you need a quality weld there is no harm in Argon purging for CS material . of course the cost will go up !
Regards
Prem Nautiyal
Godrej,Mumbai
On Tue, 16 Jun 2009 17:37:09 +0530 wrote
>OK,why SS is more suseptable than CS to get oxidised?
>
>--- On Tue, 16/6/09, Antonio Ruscitto
>
>
>From: Antonio Ruscitto
>Subject: [MW:2447] requirement of purging in CS/SS pipes
>To: materials-welding@googlegroups.com
>Date: Tuesday, 16 June, 2009, 5:02 PM
>
>
>
>Hi:
>I think that is for the same reason. Ive qualificated a Welding Procedure Specification with ASTM 106 G B, with gas purging Ar inert gas. Because that reason
>
>Regards
>Antonio
>
>>>> Sukamal Naskar
>
>
>For Stainless steel we do purging ( Inert gas like Argon ) to avoid the oxidation at the root. Stainless steel is more susseptable to oxidation than carbon steel.
>for carbon steel root is not so much suseptable to oxidation , hence we don't use purging gas like Argon.
>
>Regards,
>
>
>On 6/11/09, prashant pansare
>
>
>
>
>
>1) Why purging reqd.while welding with E316 / 316L for SS pipes?
>2) Why purging not reqd.while welding with ER 70-S for CS pipes?
>Pl. reply.
>
>
>Bring your gang together. Do your thing. Find your favourite Yahoo! Group.
>
>
>
>--
>Sukamal Naskar
>Malaysia
>
>
>
>*********************************************************************
>IMPORTANTE!
>Para evitar accidentes por inhalacin de monxido de carbono:
>- Mantenga los ambientes ventilados en forma permanente.
>- Revise que la llama sea color azul y uniforme.
>- Instale y haga revisar peridicamente sus artefactos slo a travs de gasistas matriculados.
>Recuerde que los artefactos a gas pueden emitir Monxido de Carbono: un gas altamente txico e imperceptible.
>Ms consejos en http://www.metrogas.com.ar
>*********************************************************************
>Este mensaje es privado y confidencial y va dirigido slo al destinatario indicado. Si lo ha recibido por error, por favor avsenos inmediatamente va e-mail a error-mail@metrogas.com.ar y tenga la amabilidad de eliminarlo de su sistema. La utilizacin o divulgacin de su contenido puede importar la comisin de un delito. No copie, reproduzca o divulgue -en forma parcial o total- su contenido. Cualquier opinin contenida, es exclusiva de su autor y no representa la opinin de MetroGAS S.A. - Muchas gracias.
>This message is private and confidential and it is only intended for the addressee named above. If you have received this message and it is not addressed to you, please advise us immediately at error-mail@metrogas.com.ar and kindly remove it from your system. The use or disclosure of its contents may be regarded as an offense. Do not copy, reproduce or disclose them, either partially or fully. Opinions are the exclusive responsibility of the author and do not represent the opinion of MetroGAS S.A. - Thank you.
>:: http://www.metrogas.com.ar
>
>
>
>
>
> Explore and discover exciting holidays and getaways with Yahoo! India Travel http://in.travel.yahoo.com/
>>
>
PREM S NAUTIYAL
CELL : 9820313278
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