[MW:2646] Re: 2616] Re: QW 407.3

Hi,

Hardness and Tensile strength will get reduced. Impact property will enhance.

Thanks,

K.Rajagopal

On Wed, Jul 8, 2009 at 9:00 AM, Jamie Welding <jamesmathewtrading@gmail.com> wrote:

Dear Friends,
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.
>         >>> >>
>         >>>
>         >
>         >
>         >--
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>
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