Ref. to Codes B31.3; which also accepts 10% higher values so in the
range of 256HB are all good.
Welding process was alright but looks like post heating was not
uniform as by means of electric coils.
But here now on different points on weld joint there is already like
172 HB and 238 HB (apart of 281 HB )seems hardness is below than
parent metal hardness limits (241HB), if we go for re-treatment than
there is risk of reducing more values (soften) or on other hand no
gurantee to stress relieving for whole weld joint.
If someone have an experience of a particular re-treatment of a joint
having values like 172, 281, 184 than do share please, just wondering
because re-treatment effect the whole
Again i thank you all for replying.
Thanks,
regards,
N Bhatti
On Dec 4, 12:34 am, <pgosw...@sympatico.ca> wrote:
> P-22 Hardness Issues.docx
> 912KViewDownload
>
> Hi Naveed,
>
> ASME B-31.1 does not have any restrictions on hardness limits for P-22 welds. For HRSG environments many a times the hardness restrictions are imposed by the client. ASME B-31.3 codes allows maximum values of 241 HB for P-22 weld metals .Note in majority of the instances where P-22 material is used under B-31.3 design code PWHT is mandatory based on the design requirements.
> It's prudent to have some restrictions as mentioned above.
>
> Localized hardness readings could be affected by surface prepartions.Why not take reading on other locations on the same weld and see how it differs. If the hardness reading of 281 HB is isolated , you may ignore it. If it is consistently high i.e in the vicinity of 281 BHN , then have one of the following options:-
>
> check if there is any mix-up or wrong electrode being used.
> if not, perform Re-stress relieving to bring the hardness within the acceptable limits on discussions with clients.
>
> Let me know , if it helps.
>
> Thanks.
>
> P.Goswami,P.Eng,IWE.
>
>
>
> > To: materials-welding@googlegroups.com
> > Subject: Re: [MW:13131] P22 Hardness issues
> > From: snbag...@aol.in
> > Date: Sat, 3 Dec 2011 05:39:34 -0500
>
> > Please mention your electrode composition, weld temperature, pre
> > heating and PWHT if any.
>
> > S.N.Bagchi.
> > <snbag...@aol.in>
>
> > -----Original Message-----
> > From: Vanchinath S.A. <vanchina...@gmail.com>
> > To: materials-welding <materials-welding@googlegroups.com>
> > Sent: Fri, Dec 2, 2011 10:32 pm
> > Subject: Re: [MW:13127] P22 Hardness issues
>
> > Dear Mr.Bhatti,
> > what is the thickness of weld joint? P22 material should be stress
> > relieved at 710 plus minus 20 deg C for min two hours to get hardness
> > below 235BHN.
> > vanchi
>
> > On Thu, Dec 1, 2011 at 10:25 AM, N Bhatti <naveed...@gmail.com> wrote:
>
> > Hi Experts,
>
> > I need a little favour to get some reviews/opinions about an on going
> > issues of P22 material regarding PHWT on my site.
>
> > Attached results show that PWHT has not been done effectively.
> > In the attached file here are some results of weld joint for main high
> > pressure steam line (approx. 33mm thick).
> > In weld no. 1 Each weld pass have different values i.e 172, 281 & 184
> > much difference among them. I need to know what are possible causes and
> > and now acceptance criteria.
> > Further for other joints what is your opinion in respect of acceptance
> > (ref. value is 240 or upto what value we can accept these) and at which
> > place it has been addressed in ASME B31.1 or in AS 4041?
>
> > What is the recommended treatment now?
>
> > Thanks all your time & attention.
> > Looking forward for reply please.
>
> > Kind regards,
> > Bhatti
>
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