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[MW:1869] Re: Welding Thick S500QL & S690QL plates for Hydro Power

By Materials & Welding
PWHT is generally not recommended on Q&T steels. There is no mention
of PWHT for P No. 11B material in the code also.

Post heating (Soaking) is anyways required. This is irrrespective of
PWHT.

You should meticulously monitor Preheat and Interpass temperatures for
successful welding of this material.

Regards.

Sanjay

On Apr 3, 7:17 pm, Erhan Turgut <ertur...@gmail.com> wrote:
> Hi,
> We're working on 2700 mm dia. pipes with a thickness range of 26 - 40 mm
> for S500QL and 30 - 48 mm for S690QL.
> These penstocks will be used in hydro power plant with a pressure of
> aprx. 140 bar
> We have two methods for welding: SAW on GTAW (root GTAW, fill & cap SAW)
> and SMAW on GTAW. We will try to achieve max. 12 kJ/cm heat input.
> So shall we apply PWHT (Stress relief)? If yes what is the thickness
> limits for PWHT.
> We planned to apply Soaking (Hydrogen Releasing) with a temperature of
> aprx 250 oC for 2.5 - 3 hours. So if we apply Stress relief
> heat-treatment with a temp. of 550 oC for 1 hour do we have to apply
> soaking anyway?
>
> Thanks in advance
> Regards,
>
> Erhan TURGUT

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