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RE: [MW:15148] Problem about Positive material Identification (PMI)

You have to try one joint with thin layer of welding with filler wire having correct composition of crome and then do the pmi then see the result.
-----Original Message-----
From: "kulandaivel__subramani_"
Sent: 28/08/2012, 6:20 PM
To: materials-welding@googlegroups.com; "mohamed jubair"
Subject: Re: [MW:15145] Problem about Positive material Identification (PMI)


Check with another PMI equipment preferably using XRF equipment.

On Tue, 28 Aug 2012 13:55:05 +0530
mohamed jubair <kmd.jubair@gmail.com> wrote:
> Dear all,****
>
> ** **
>
> In our boiler one major problem occurred in Positive
>Material
> Identification(PMI) test [Spectrum test]. ****
>
> ** **
>
> Description****
>
> Reheater finishing outlet(RHFO) coil****
>
> Material****
>
> T91****
>
> Size****
>
> ø 63 x 4****
>
> Process****
>
> GTAW only****
>
>Filler wire****
>
> ER 90S B9****
>
>Filler wire Manufacturer****
>
> D & H Secheron****
>
> Preheating °C****
>
> 185****
>
> Rate of Heating °C****
>
> 100/hr****
>
> Interpass temp °C****
>
> 190****
>
> Post heating °C****
>
> 100****
>
> PWHT °C****
>
> 750****
>
> Soaking Time****
>
> 90 minutes****
>
> ****
>
> Around 800 joints welded in the above approved procedure
>only. Filler wire,
> header stub, RHFO coil, weld metal undergone PMI test
>separately and all
> show positive material results as T91 except weld metal.
>Weld metal shows
> the Chromium content only as (4-7%){Reqd is 8-10.5%}.
> We can't find how
> it happened? Our Chinese consultant told to cut and
>reweld all the joints.
> But our contractor argued that we followed approved
>procedure and used
> approved vendor's consumable only. Please give a
>solution. Here I have
> attached one preheating cum PWHT chart of RHFO
>joints(for 11 joints,5
> thermocouples,1 recorder).All 800 joints are not checked
>yet. Only 40
> joints checked and all 40 weld metals shown low Cr
>Content.**
>
>
> Please go through the below readings of one RHFO
>joint.****
>
> *Description*
>
> *Filler wire*
>
> *Header stub*
>
> *Weld metal*
>
> *RHFO coil*
>
> Alloy****
>
> T91****
>
> T91****
>
> A-2****
>
> T91****
>
> Cr****
>
> 8.94****
>
> 8.34****
>
> 5.19****
>
> 8.68****
>
> Mo****
>
> 0.96****
>
> 0.90****
>
> 0.93****
>
> 0.92****
>
> V****
>
> 0.17****
>
> 0.17****
>
> 0.08****
>
> 0.19****
>
> Ti****
>
> 0.07****
>
> 0.10****
>
> 0.04****
>
> 0.03****
>
> Mn****
>
> 0.60****
>
> 0.40****
>
> 0.54****
>
> 0.63****
>
>Fe****
>
> 87.81****
>
> 88.11****
>
> 90.86****
>
> 87.61****
>
> Ni****
>
> 0.12****
>
> 0.33****
>
> 0.20****
>
> 0.38****
>
> Cu****
>
> 0.02****
>
> 0.16****
>
> 0.20****
>
> 0.16****
>
> Nb****
>
> 0.09****
>
> 0.08****
>
> 0.03****
>
> 0.04****
>
> W****
>
> 0.15****
>
> ****
>
> 0.00****
>
> ****
>
> ** **
> Waiting for your valuable suggestions.
>
> Thanks & Regards
> K Mohamed Jubair
>
> --
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>
> 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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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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To unsubscribe from this group, send email to materials-welding+unsubscribe@googlegroups.com
For more options, visit this group's bolg at http://materials-welding.blogspot.com/
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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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