RE: [MW:11851] T91+SS welding

Dissimilar welds involving P91, P11 and P22 and austenitic stainless steels are performed on a routine basis in super critical boilers. Typical systematic approach to such welds should as follows:-

Butter, P-91, with Nickel based GTAW filler(Inconel 82). Typical buttering thickness 5-6 mm after grinding.(Table-1)
PWHT P-91 steel.(see Table-2)
Perform welding between buttered and PWHT-ed P-91 steel to austenitic 304H S.S.Use Inconel /82/182 as required without further PWHT.

Hope this would clear the various doubts raised by this query.

Thanks.

Pradip Goswami,P.Eng.IWE
Welding & Metallurgical Specialist & Consultant
Ontario,Canada.
Email-pgoswami@sympatico.ca,
pgoswami@quickclic.net

Table-1,Dissimilar Weld Combinations and Approach

Table-2,Recommended PWHT Temperatures (0F) for Dissimilar Welds

-----Original Message-----
From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of Ramin Kondori
Sent: Thursday, July 21, 2011 12:17 PM
To: materials-welding@googlegroups.com
Subject: Re: [MW:11849] T91+SS welding

Dear S.Nareshkumar:

Tricky Subject...
Study the attached file
In page 3, you sea two figures (left diagram) that show the required Heat treatment and Temp. control during welding for P91 (that is same as T91) and you will realize that T91 definitely needs to be post-weld heat treated in 760 degrees...
This is bad for 304, very bad...

BUT

Please give me more details on the location of the joint and the service conditions.
And why are you welding these two materials together...?
Couldn't you use flanged joints instead...?

I think eventually, it's easier to change the design (if possible)...

Anyway, please send more details...!!!

Regards
Ramin Kondori
IWE AT 0070

----------------------------------------------------------------------------------------------
*********************************************************************************

On 7/18/11, Naresh Kumar <snareshkumar30@yahoo.com> wrote:
> Dear friends,
> Any one guide me whether SA213 T91+SA213 TP304 welding PWHT require or not.
> Filler wire used:
> ER NiCr3
>
> Regards,
> S.Nareshkumar
>
> --
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--
Ramin Kondori
* QC/Welding Engineer *
* IWE AT 0070*
**

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For more options, visit this group's bolg at http://materials-welding.blogspot.com/
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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