Thanks for the valuable comments. I refered in ASME SEC VIII, its
clearly stated. But what about the limits based on AWS D1.1? And also
guide me for the Rate of heating and rate of cooling for PWHT? What
are the factors involved to decide the rates?
On 1/21/12, james gerald <gerry_tup@yahoo.com> wrote:
> Preheat is a function of many parameters like
> a. Carbon Equivalent (for Carbon steels)
> b. Material Type
> c. Thickness (Restraint)
> d. Hydrogen level
>
> For materials covered under ASME Sec.II, below mail from Mr.John Henning
> will provide a guidance based on construction codes
>
> For structural material , Appendix in AWS D1.1 will provide guidance.
>
> Interpass temperature is also an important parameter for which maximum
> values are specified in the WPS. Generally
>
> For Carbon & Chrome-moly steels - 300 to 350 degC max
> For Stainless Steel - 175 degC max
> For Nickel ALloys - 150degC max
> For superaustenitic steels - 98degC max
>
> Increasing the Interpass temperatures above the prescribed values will
> result in Grain coarsening, sensitisation, hot cracking, precipitate
> formation etc.. depending upon material type.
>
> Thanks & Regards
>
> J.Gerald Jayakumar
> 0091-9344954677
>
>
> ________________________________
> From: John Henning <jhenning@deltak.com>
> To: materials-welding@googlegroups.com
> Sent: Friday, January 20, 2012 9:12 PM
> Subject: [MW:13527] RE: 13526] Preheat & Interpass temperature - Reg
>
> Typically preheat recommendations will come from the construction Code
> (for example Section I - PW38, Section VIII - Appendix R, or UCS-56
> notes). High restraint, or other factors, may result in using a higher
> preheat than recommended/specified in the code. General rule of thumb
> for interpass; 600F max. for carbon and alloy steels {Q&T or specialty
> steels - consult material supplier}, 350F max for stainless, and 300F
> max for duplex stainless and nickel based.
>
> John A. Henning
> Welding & Materials
>
> -----Original Message-----
> From: materials-welding@googlegroups.com
> [mailto:materials-welding@googlegroups.com] On Behalf Of Ramesh
> Deenathayalan
> Sent: Friday, January 20, 2012 1:40 AM
> To: materials-welding@googlegroups.com
> Subject: [MW:13526] Preheat & Interpass temperature - Reg
>
> Dear friends,
>
> While writing the WPS based on ASME SEC IX, how can we determine the
> minimum preheat temperature and maximum interpass temperature?? Kindly
> advice.
>
> Ramesh D
>
> Sent from my Nokia phone
>
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> The views expressed/exchnaged in this group are members personel views and
> meant for educational purposes only, Users must take their own decisions
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> The views expressed/exchnaged in this group are members personel views and
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--
With Regards...
♠ Ramesh D ♠
Ph: +919677185585.
--
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The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.
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