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Up Topic Welding Industry / Technical Discussions / Gr 91 welding and post heating
- - By justin81 Date 12-07-2018 07:53
In Gr91 material, shall we have to go for post heating and if so what are the uses of it?  What is the time gap recommended between completion of welding and post weld heat treatment?
Parent - By Lawrence (*****) Date 12-07-2018 17:21
Yes.  Post heat is required

Walt Sperko provides an excellent place for you to *start* your research.

http://www.sperkoengineering.com/html/Grade%2091%20R%2010-05.pdf

Keep in mind compliance to whatever codes or standards your work must obey.
Parent - By Jim Hughes (***) Date 12-10-2018 14:50
justin81,
The answer to your first question is Yes, as Lawrence mentioned . The next question is hard to answer on this site. You can e-mail me and I would be willing to give you some more in-depth understanding of PWHT.  PWHT is mandatory on all P91 material after welding. Immediate PWHT after bake out and the material has cooled to 200 Deg. f is recommended. But, EPRI (Energy Power Research Institute) and other industry SME's recommend no more than 7 days after welding and bake out to perform PWHT. EPRI is the leading organization for all things P91.  They have a web site you can tap into. Some of their info is free and some is very expensive and requires membership. Be advised that this material requires detailed procedures for pre-heat, welding, NDE, hardness testing and PWHT and based on your post, I would highly recommend consulting SME's for assistance. This material, if not joined correctly can be very problematic and can be prone to failure.
- - By Aanish Date 10-22-2020 02:39
Hi can anyone direct me to the book where i can find the requirement of postheating, temperature range and duration. I know that we do post heating after welding for CrMo steel, low alloy steel and carbon steel with CE>0.45% but i dont know which code help us to understand and perform it in the right way.
Parent - By Jim Hughes (***) Date 10-27-2020 13:55
EPRI has some great information on this material. Look for EPRI doc# 1024713 (Creep Strength–Enhanced Ferritic (CSEF) Steel
Welding Guide)  EuroWeld has some good information since they are very instrumental in assisting with the EPRI papers.
- By Noking Date 06-13-2023 08:55
What effect will occur if PWHT performs more than a limited time (7 days), Can anyone kindly explain to me?
Up Topic Welding Industry / Technical Discussions / Gr 91 welding and post heating

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