Hardness Of P-91 Material

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pradip kumar Sil

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Jan 30, 2016, 12:14:02 AM1/30/16
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Dear Everybody,

Some of our P-91 Joints( Weldment) are coming hardness value around 300HB in the HRSG Unit.
 Joints thickness is 18 mm & 20 mm & we did PWHT 2 hours holding time at 710 degree centrigrade also we did 150 degree heating rate ,120 degree cooling rate.

Can you pls suggest us this hardness value  is acceptable in the HRSG unit. If not pls suggest me how to recover.
Regards,
Kumar

Mohammad Saquib

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Jan 30, 2016, 12:23:13 AM1/30/16
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Dear Kumar,
you have to do re PWHT 2 hours holding time at 725 degree centrigrade  make sure the heating & cooling rate is not more than 100 degree

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Naresh Kumar

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Jan 30, 2016, 4:07:34 AM1/30/16
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Dear Mr.Kumar

Normally 760 C with 4 hours holding time required to get a hardness value.But always follow your WPS requirements and client specifications. 


Thanks & Regards
Nareshkumar Subramanian




From: Mohammad Saquib <saqui...@gmail.com>
To: "material...@googlegroups.com" <material...@googlegroups.com>
Sent: Saturday, January 30, 2016 9:20 AM
Subject: Re: [MW:24188] Hardness Of P-91 Material

Mansukh Satashiya

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Jan 30, 2016, 7:26:28 AM1/30/16
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Dear friend
Do heating and cooling rate 60 degree per hour and do proper booth preparation with teen sheet and do not open up to 24 hours after pwht complete
We are doing 52 mm thick p91 joints
Mansukh Satashiya

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pradip kumar Sil

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Jan 30, 2016, 7:37:41 AM1/30/16
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Here temp is 2- 3 degree centrigrade...... After PWHT next day we exposed all joints open atmosphere.
Is any effect to increase the hardness.
Pls advice me

Karthikeyan Shanmugananthan

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Jan 31, 2016, 3:59:59 AM1/31/16
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Please ref ASME B 31.1 TABLE NO. 331.1.1 or NACE MR 0103 for hardness requirements and also maintain voltage & amps less than required ileveln each layer to obtain hardress valve with in limit

Regard
S.karthikeyan

elias jarjoura

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Feb 2, 2016, 6:29:04 AM2/2/16
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Pre-heat and PWHT as per approved or adopted PQR and WPS.
 


Date: Sat, 30 Jan 2016 09:59:36 +0500
Subject: [MW:24187] Hardness Of P-91 Material
From: prad...@gmail.com
To: material...@googlegroups.com

Mostafa Kamel Hussein

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Feb 2, 2016, 10:38:10 PM2/2/16
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preheat & PWHT should be carried out based on the approved WPS. chart of preheat & PWHT should be in a continuous chart. 


Mohd Siraj

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Feb 3, 2016, 12:14:33 AM2/3/16
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pradip,

what basis u select 710C??

you neither mentioned any process nor consumable??

pl tell us what is Ni+Mn is more than 1.5??

@760C+/-14C for two hr should be done.

Kannayeram Gnanapandithan

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Feb 3, 2016, 1:36:28 AM2/3/16
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if Ni+Mn is more than 1.5, then it will reduce the lower critical temp which is not comfortable to do PWHT at 750-760 deg Celsius. Since hardness is more re do pwht at 750-760

THANKS & BEST REGARDS,
KG.PANDITHAN, IWE,  AWS-CWI, CSWIP 3.1,
CONSULTANT-WELDING & QUALITY

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afrozsh...@gmail.com

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Feb 18, 2016, 4:40:49 AM2/18/16
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Dear Kumar,

Please do the PWHT By Induction heating method and keep the heating &cooling rate 80 -100 Deg C.Also do post heating for 4 hours.

Regards,
Afroz Shaikh

Kannayeram Gnanapandithan

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Feb 18, 2016, 6:56:17 AM2/18/16
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MINIMUM PWHT TEMP IS 730 DEG CELSIUS. ITT IS BETTER TO DO AT 760+- 10 WITH  30MINUTES MINIMUM

THANKS & BEST REGARDS,
KG.PANDITHAN, IWE,  AWS-CWI, CSWIP 3.1,
CONSULTANT-WELDING & QUALITY

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