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Re: [MW:13354] Oxygen level in purging gas during welding of duplex stainless steel

By Materials & Welding
Dear Mr Martin,

As we done here SDSS fabrication we are
following client Spec, Only up to completion of root pass, Oxygen
level shall be below -100 ML/Ml3, During welding if exceed 500 Ml/Ml3
then welding has to stop,this process follow up to three layer.

Depending upon you thickness of deposit. After three layer heat input
cannot oxidize the root, It optional u can maintain up to 10 mm thick
welding ,if pipe thickness is more than 10mm u can stop backing gas .


Regards

Madhu


On 12/28/11, Martin Prad <martin_prad@hotmail.com> wrote:
>
> Hi friends,
>
> I have 2 different specification which the requirements are different for
> the oxygen level in purging gas during the welding of super duplex pipe.
>
> One of them calls for 25 ppm (0.0025%) another one calls for 5000 ppm
> (0.5%). Could you please shed some light on this as which one is up to the
> standard with references?
>
> Thanks,
> Martin.
>
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