Duplex Claded Eqipt PWHT

[Prakash Hegde]

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

 

[Pieper QSI]

Dear Mr. Hedge,

 

When executing PWHT at 600 °C your corrosion resistance will be reduced because of the formation of Sigma phase (FeCr precipitates) in the microstructure of the cladding. Sigma phase can occur in the temperature range from 450 °C – 850 °C so if you will discuss lowering the PWHT temperature you should go for 400 max. but I would choose to propose withholding PWHT and take care of controlling welding parameters during production.

You may propose executing portable MicroVickers hardness tests after weld completion in order to demonstrate no high hardness values are present at the HAZ near weld surface.

Most important is to convince your client to withhold PWHT because of the corrosion resistance of the cladding. When client insist on any kind of stress relieve treatment you perhaps can convince them to use high frequency hammering of the cap layer and HAZ. This will introduce compressive stresses in the surface up to 2 mm instead of the tensile stresses present after welding.

 

Met vriendelijke groeten / Best Regards

 

Herman Pieper

 

Pieper Quality Support & Inspection

Phone: +31 (0)521 380083

Fax:     +31 (0)84 7539225

Cell:     +31 (0)6 51691215

www.pieper-qsi.nl

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[Prakash Hegde]

Dear Mr Herman Pieper

Thanks for Suggestion

My openion ,which can be debated

i) If I carry out restoration of cladding by barrier layer of ry 309LMo chemistry  and carry out PWHT as per code

ii)After PWHT go for rest of the layer by Duplex electrode and no further PWHT

(Of course PQR is to be qualified accordingly)

What is your openion ?

Regards

Hegde P.B.

---

From: Pieper QSI <piepe...@kpnmail.nl>
To: material...@googlegroups.com
Sent: Fri, 29 April, 2011 12:51:54 PM
Subject: [MW:10883] RE: 10879] Duplex Claded Eqipt PWHT

[arijoy roy]

I have one more point to add after cladding, sometime you may find cracks . But these cracks usually do not extend upto the base material and usuallydo not propogate during service. Therefore there usually is no need for PWHT. With regards Arijoy Roy R&D Telcon , India. --- On Fri, 29/4/11, Pieper QSI <piepe...@kpnmail.nl> wrote:

[manish kulkarni]

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.h...@yahoo.com> wrote:

From: Prakash Hegde <pb.h...@yahoo.com> Subject: [MW:10879] Duplex Claded Eqipt PWHT To: material...@googlegroups.com

[Vanchinath S.A.]

No PWHT for duplex clad as temp between 300 to 850 degC will form intermetallic phases and affect the corrosion properties. suggest  u carry out PWHT of equipment  with barrier layer of 309L Mo  and then deopsit duplex over barrier layer.

regards

vanchi

--

[arijoy roy]

Dear Mr. Kulkarni The Cr overlay is usually for a dual purpose for anticorrosion and wear resistance. What is the performance of the incolloy with respect to wear resistance With Regards Arijoy roy --- On Sat, 30/4/11, manish kulkarni <kul_m...@yahoo.co.in> wrote:

[pgoswami]

Mr. Hegde,

 

As per UHA-32;-For the austenitic-ferritic wrought or cast duplex stainless steels, post weld heat treatment is neither required nor prohibited, but any heat treatment applied shall be performed through exposure of the alloy between 1000-1100 deg C and  followed by liquid quenching or rapid cooling by other means. Ideally the most appropriate post weld heat treatment for Duplex S.S is solution anneal.

 

The same analogy may not work (difficult to practice) for a duplex clad carbon or low alloy steel plates.PWHT at the solution anneal temperature is not feasible for  fabricated vessel/equipments. As pointed out by Mr. Kulkarni  and Mr. Herman Pieper  PWHT in the range of 610 deg C  could severely embrittle the  duplex , through formation intermetallic phases such as  sigma and Chi phases.The chances would be more pronounced for super duplex 2507 than 22Cr duplex e.g UNS 31803.

 

One feasible option could be PWHT at lower temperature for extended period of time(UCS-66). I would feel a PWHT @ 450deg C would be sensible. However meeting all  design code (ASME or others) requirements and additionally corrosion test e.g  IGC,Pitting corrosion,etc  as per G-48 needs to be established during PQR qualifications. It may worthwhile to run procedure qualification test with matching duplex S.S consumables and superior austenitic consumables such as E-NiCrMo-3(Incol 625) to see the relative merits and demerits.

 

All may not be that deadly with lean and medium alloyed duplex S.S e.g S 31803. The attached article provides a good insight on various detrimental phases and their formation mechanisms at various temperatures.

 

Thanks.

 

Pradip Goswami,P.Eng.IWE

Welding & Metallurgical Specialist & Consultant

Ontario,Canada.

Email-pgoswami@sympatico.ca,

pgos...@quickclic.net

[Prakash Hegde]

Dear Mr Goswami

Thanks for information about PWHT of Duplex clad

Should we presume that

i) Duplex clad on CS base can be stress relieved between 400-450 C with extended time

ii) However in case of Duplex clad on P4 base material we can not have PWHT temp below 650C with extended Time (As ASME code does not give exemption) In such case what should be our stand ?

iii)Can we avoid PWHT of Eqpt having Clad of Duplex steel on P4 material?

With regards

 

Hegde P.B

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

From: Prakash Hegde <pb.h...@yahoo.com> Subject: [MW:10879] Duplex Claded Eqipt PWHT To: material...@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

-- To post to this group, send email to material...@googlegroups.comTo unsubscribe from this group, send email to materials-weld...@googlegroups.comFor 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. -- To post to this group, send email to material...@googlegroups.comTo unsubscribe from this group, send email to materials-weld...@googlegroups.comFor 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.

-- To post to this group, send email to material...@googlegroups.comTo unsubscribe from this group, send email to materials-weld...@googlegroups.comFor 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.-- To post to this group, send email to material...@googlegroups.comTo unsubscribe from this group, send email to materials-weld...@googlegroups.comFor 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.

[Karthik]

Hi, As per UCL-34,Vessel Shall be Heat treated with Cladding.In your case PWHT can not be avoided. UCL-34 (a) Vessels or parts of vessels constructed of base material with corrosion resistant integral or weld metal overlay cladding or applied corrosion resistant lining material shall be postweld heat treated when the base material is required to be postweld heat treated. In applying these rules, the determining thickness shall be the thickness of the base material. When the thickness of the base material requires postweld heat treatment, it shall be performed after the application of corrosion resistant weld metal overlay cladding or applied corrosion resistant lining unless exempted by the Notes of Table UCS-56. Thanks & Regards, (Karthik) Karthikeyan.S QA/QC Manager Getabec Energy Co.,Ltd. 379,Moo6,Soi8,Nikhomphatana, Rayong-21180, Thailand. Phone: 0066 38 897035-8 (Off) Fax: 0066 38 897034 Hand Phone: 0066 892512282

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