Re: [MW:13471] amendment for this WPS regarding

Hi,

Welding of Ferritic-Austenitic Steels:

These steels with a two-phase structure of delta-ferrite and austenite are defined as Duplex-steels. They are well-suited for fusion welding. 

• Highest admissible operating temperature for welded structures is 250°C. In the temperature range between 250 to 900°C there will occur a decline in toughness due to the 475°C embrittlement and the formation of brittle intermetallic phases.
• Weld consumable of the same nitrogen-alloyed composition, the nickel content of which being slightly increased for limiting the delta-ferrite content in the weld metal. Admixture from the less nickel containing steel should not exceed 40%. Welding without adding weld metal only possible with subsequent solution annealing and quenching.
• Welding without preheating, interpass temperature max. 250°C (steels having about 23% Cr) or max. 150°C (steels having about 25% Cr).
• Heat input is chosen a bit higher as in welding austenitic steels. Depending upon welding procedure, thickness of workpiece etc., welding is carried out at 5 to 25 kJ/cm (steels with about 23% Cr) or at 2 to 15 kJ/cm (steels with about 25% Cr).
• Possessing high contents of delta-ferrite, steels are susceptible to hydrogen induced cracking. Therefore, hydrogen pick-up during welding shall be kept low (e.g. by redrying covered electrodes, no hydrogen bearing shielding gas).

As per API582 recommendations,Interpass temperature for P.No.8 material shall not be more than 175 degrees. So if you weld dissimilar joint,this this recommendation shall be followed.

 

Thanks & Regards,

(Karthik)

Karthikeyan.S

QA/QC Manager

German-Thai Boiler Engineering Cooperation Limited.

Rayong Factory ;

379 Moo.6 Soi 8, Tambol Pananikom,

Nikompattana, Rayong 21180 THAILAND

Tel : +66 38 897 035-9 Ext. 137

Fax : +66 38 897 034

Hand Phone: 0066 892512282

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From: Lakshman Kumar.B <lakshmankumar4@gmail.com>
To: materials-welding@googlegroups.com
Sent: Friday, January 13, 2012 12:30 PM
Subject: RE: [MW:13469] amendment for this WPS regarding

Dear Karthik,

 

Shall I know that the interpass temp must be maximum of 175 deg, shall I request in which clause it was detailed? I am in struck up of an issue in the same regard, and u r info will be helpful for me.

 

Thanks and Regards................?

Lakshman Kumar.B|Manager |Lanco Infratech Limited Plot No 1255 | Sanjeevani chowk | Mahanadi vihar | Cuttack 753004 Phone : + 91 671 2445033 | Mobile : +91 9937286851 |www.lancogroup.com Go Green|The future will thank you

 

 

From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of Karthik
Sent: Friday, January 13, 2012 9:09 AM
To: materials-welding@googlegroups.com
Subject: Re: [MW:13468] amendment for this WPS regarding

 

Hi,

As per QW406.1 and 406.3,Preheat temperature and Interpass temperature shall be specified on the WPS. 

Option-1:

What is the Preheat and Interpass temperature recorded on the PQR? If you didn't do preheat while doing PQR,you can revise the WPS as ambient and Interpass temeprature as maximum recorded on the PQR. Since it is dissimilar joint, it shall not be more than 175 degrees(Maximum).

Option-2:

If you did preheat while doing PQR, your WPS shall be specified the Preheat Temp.For example if you Did or  plan to do preheat of 150degrees on PQR,your WPS shall be specified as 95degrees(Minimum). Because as per QW-406.1 A decrease of more than 100°F (55°C) in the preheat temperature qualified is an essential variable.Also you can specify Interpass temeprature as maximum recorded on the PQR but it shall not be more than 175 degrees(Maximum).

 

Thanks & Regards,

 

(Karthik)

 

Karthikeyan.S

QA/QC Manager

German-Thai Boiler Engineering Cooperation Limited.

Rayong Factory ;

379 Moo.6 Soi 8, Tambol Pananikom,

Nikompattana, Rayong 21180 THAILAND

Tel : +66 38 897 035-9 Ext. 137

Fax : +66 38 897 034

Hand Phone: 0066 892512282

 

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From: venkateswaran k <kvnkat@rediffmail.com>
To: materials-welding@googlegroups.com
Sent: Thursday, January 12, 2012 3:25 PM
Subject: [MW:13460] amendment for this WPS regarding

 

Dear All,

We qualified WPS for Material SA 516(P:1,G:1) TO SA240TP 316L(P:8,G:1) by SMAW process as per ASME Sec IX ,thickness range- base metal Grove is: 5 -30 mm,Filler metal:E309 Mol.

My question is while qualifying we did not mentioned Preheating and Inter pass temperature (in WPS -QW 406),now one of our client asking for these two parameters need to be filled /required, in this case how to convince him. Whether can I make amendment for this WPS, it is acceptable as per ASME Sec IX. If yes can u provide format for this amendment.

kvr

 

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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.