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Re: [MW:10889] Duplex Claded Eqipt PWHT

By Materials & Welding
Dear Mr.Hegde,
 
You have not specified composition of overlay -22 Cr or 25 Cr.
The DSS overlay and subsequent PWHt at 600 Deg.C is not advisable primarily for Alfa Prima microstructure which is likely to form in this temp. range. Corrosion tests ( G 48) and Hardness test may reveal this.However it is difficult to take out sample for G 48 test with 3 mm overlay on CS.
 
Probable solutions-
 
1) Incolloy 625 overlay instead of DSS.
2) Carryout PWHT after completion of overlay after first pass and overlaying other passes after PWHT.
3) Carryout SSC/SCC test with Simulation heta treatment for the process conditions as stated in NACE.
 
Regards,
 
Manish Kulkarni

--- On Fri, 29/4/11, Prakash Hegde <pb.hegde@yahoo.com> wrote:

From: Prakash Hegde <pb.hegde@yahoo.com>
Subject: [MW:10879] Duplex Claded Eqipt PWHT
To: materials-welding@googlegroups.com
Date: Friday, 29 April, 2011, 10:01 AM

Dear Friends
I have a query about The Duplex  cladded E quipment having base material SA 516 Gr70 of 50mm thk and clad of Duplex (3mm )
The eqipment require to undergo PWHT at 600C The Joint is clad restored by Duplex weld
 
i) Does the PWHT at 600C will affect  the Corrosion properties of Duplex weld (Corrosion test like IGC,Pitting corrosin,etc  as per GS8)
ii) If yes do we require to carry out PWHt at lower Temp.
 
Regards
Hegde P.B.
08805593046
 
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