Mr. Jubir,
Noted the points mentioned by you. If the filler materials were pre checked and found to be OK for its chemistry, then there can not be any reason for such a drastic change in the post weld chemistry, i.e., from 9% to 4%.
The pre, inter pass, post heat or PWHT temp. as mentioned by you are all within the stipulated range and can not be a reason either.
All the 800 joints can not go wrong at a time unless something happened drastically. Have a random check (date wise fabrication) again and find if the Cr. deficiency is same with all the joints. It may give an insight and may lead to a conclusion.
regards,
Sridhar.
From: mohamed jubair <kmd.jubair@gmail.com>
To: materials-welding@googlegroups.com
Sent: Thursday, 30 August 2012 1:49 PM
Subject: Re: [MW:15164] Problem about Positive material Identification(PMI)
Dear Mr. Sridhar
Thanks for your suggestion.
Please understand my point. The filler wire readings mentioned in the table(trailing mail) is not from the manufacture's test certificate but from Positive material identification(PMI). In PMI test two parent metals,filler wire showing positive values as T91 but weld metal only not conforming as T91.
We procured other two new batch filler wires from the same manufacturer,welded and checked. It shows positive material for all the four(two parent metal,weld metal,filler wire) as T91.
Regards
Jubair
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