I would like to know the effect of higher soak time on the
metallurgical properties of the metal as this is a supplementary
essential variable as per QW 407.2
On Jul 6, 7:11 pm, "John Henning" <jhenn...@deltak.com> wrote:
> (1) QW-407.2 is, typically, a supplementary essential variable - see
> tables QW-252 through QW-265. That is, it applies only if impact
> testing is required.
>
> (2) The DBTT is typically shifted to higher temperatures with greater
> time at temperature during sub-critical PWHT. (DBTT = ductile to brittle
> transition temperature)
>
> (3) Therefore, the Code is concerned that, at a minimum, the PQR PWHT
> time at temperature must be at least 80% of the actual fabrication PWHT
> time. The PQR PWHT time can be longer than but not shorter than the 80%
> requirement.
>
> In my experience, this is why general PQR's for impacts are performed
> with long PWHT times - often 8 to 24 hours. If acceptable results are
> obtained (at the given test temperature) at long hold times then the PQR
> and WPS will be valid for much greater thicknesses or long aggregate
> times if multiple PWHT's are planned. Note that low temperature holds
> for the purpose of hydrogen bake out are not required to be included
> (600~800F / 315~425C) by ASME Code. But may be required to be included
> by customer specifications or other codes.
>
> John
>
> ________________________________
>
> From: materials-welding@googlegroups.com
> [mailto:materials-welding@googlegroups.com] On Behalf Of Shashank Vagal
> Sent: Friday, July 03, 2009 2:05 AM
> To: materials-welding@googlegroups.com
> Subject: [MW:2616] Re: QW 407.3
>
> The underlying meaning eludes me; why would one want to increase the
> soaking time at an additional cost and what not, over and above the WPS
> allowed one by way of a PQR? Something jinxes.
> Shashank Vagal
>
> --- On Tue, 30/6/09, PREM SHANKARDUTT NAUTIYAL
>
> <prem_nauti...@rediffmail.com> wrote:
>
> From: PREM SHANKARDUTT NAUTIYAL <prem_nauti...@rediffmail.com>
> Subject: [MW:2594] Re: QW 407.3
> To: arunv...@gmail.com
> Cc: materials-welding@googlegroups.com
> Date: Tuesday, 30 June, 2009, 10:15 AM
>
> I think it is QW-407.2 you guys are referring, because QW407.3
> does not appear in Sec.IX 2007 edition !
>
> Regards
>
> Prem Nautiyal
>
> On Sun, 28 Jun 2009 19:41:18 +0530 wrote
> >you are right, rajagopal
> >arun
> >
> >On Sun, Jun 28, 2009 at 11:28 AM, rajagopal kannan <
> >rajagopal.kan...@gmail.com> wrote:
> >
> >> Hi,
> >> That is if you do heat treatment of your PQR Test coupon to
> 80 minutes
> >> soaking time, then you can write a WPS for production welds
> to the maximum
> >> of 100 minutes soaking time.
> >> Thanks,
> >> K.Rajagopal
> >>
> >> On 6/27/09, Jamie Welding wrote:
> >>>
> >>>
> >>> Hi folks,
> >>> Can any one of u interpret the QW 407.3.
> >>> Especially the part PQR should be at least 80% aggregate
> times that in
> >>> production welds.
> >>> >>
> >>>
> >
> >
> >--
> >ARUNVANI
> >
> >Smiling Opens the Heart
> >
> >Good feelings for others are like ointments that heal wounds
> and
> >re-establish friendships and relationships. Good feelings are
> generated in
> >the mind, are transmitted through your attitude and are
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> miracles
> >happen.
> >
> >SMILE IS A COOLING SYSTEM OF HEART,
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> SYSTEM OF
> >MIND....
> >SO TO ACTIVATE ALL YOUR SYSTEM
> >==ALWAYS KEEP SMILING==
> >
> >>
> >
>
> PREM S NAUTIYAL
>
> CELL : 9820313278
>
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