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[MW:2667] Re: purging gas-reg

By Materials & Welding
Dear Ganeshan,
As per API RP 582 section 7 (Shielding and Purging Gases) - Back purging is required for the GTAW and GMAW
processes for welding materials having a nominal chromium content greater than 2 1/4% unless the joint is ground or back
gouged to sound metal.
Regards
Tong2je


On Sat, Jul 11, 2009 at 1:05 PM, Nikhil <nikhilrp_2006@rediffmail.com> wrote:
Dear Mr Ganeshan,

As per basic welding fundamentals and good engineering practice, any Chrome-bearing steel need to be purged on other side during GTAW welding.

Chromium has greater affinity for oxygen when heated and get oxidized at once, which in turn depletes the chromium content in the grains. The properties of the steel will get badly affected with this chromium depleted material.

Hence, back purging for T91 is must.

Kind Regards,

Nikhil Parikh
QC Engineer, GDP, Sharjah, UAE
+97150 1453525


On Sat, 11 Jul 2009 08:10:01 +0530 wrote

>
>
>Dear Sir,
>
>Plz. any body can help to me.
>
>
>SA 213 T91 (P5B G 2) the mentioned material purging required (or) not required. If required where given in code.
>
>..
>Thanks & Regards,
>
>K.GANESAN
>Quality Control
>ISGEC / ISGEC John Thompson,
>A-4 Sector-24 Noida-201301 (UP)
>Tel. +91-120-2411175
>Direct Tel. +91-120-2411175
>Mobile : +91-9952166894
>
>
>      See the Web's breaking stories, chosen by people like you. Check out Yahoo! Buzz. http://in.buzz.yahoo.com/

>>
>



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