Wednesday, September 22, 2010

[MW:7153] RE: 7143] ISR of P-91 pipes.

ISR is beneficial in reducing hydrogen and thereby minimizing the potential for hydrogen assisted cracking (cold cracking).  ISR is typically performed by heating for 2 to  4 hours at temperatures between 800 and 1100 F (usually a customer requirement will apply)

 

More importantly – As Welded 91 is susceptible to stress corrosion cracking in the presence of water.  ISR may increase the potential for SCC by promoting secondary hardening.  You must provide a means to keep these welds warm and dry – no rain, no splashing, no dew formation, etc – best kept indoors in controlled environment.    Additional warning - SCC can be very difficult to detect.

 

John

 

From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of Ravinder Sharma
Sent: Wednesday, September 22, 2010 5:49 AM
To: materials-welding@googlegroups.com
Subject: [MW:7143] ISR of P-91 pipes.

 

Hi All,

 

I have welded joint of P91 of 400DN and 40 mm thickness, due to unavoidable reasons we have to do the heat-treatment after 60 days,

 

Is there requirement of ISR?

 

If yes, what should be the heating cycle?

 

Regards

Ravinder Sharma

--
To post to this group, send email to materials-welding@googlegroups.com
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/
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.

No comments:

Re: [MW:34832] Inquiry about Single Bevel with Back Grinding

Dear Uday, As per your question that one is called with backing only,Simple both side you are welding it is backing with strip or without st...