Monday, January 23, 2012

Re: [MW:13548] RE: 13526] Preheat & Interpass temperature - Reg

Dear ppl,

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
>
> --
> To post to this group, send email to materials-welding@googlegroups.com
> To unsubscribe from this group, send email to
> materials-welding+unsubscribe@googlegroups.com
> For more options, visit this group's bolg at
> http://materials-welding.blogspot.com/
> 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.
>
> --
> To post to this group, send email to materials-welding@googlegroups.com
> To unsubscribe from this group, send email to
> materials-welding+unsubscribe@googlegroups.com
> For more options, visit this group's bolg at
> http://materials-welding.blogspot.com/
> 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.
>
> --
> To post to this group, send email to materials-welding@googlegroups.com
> To unsubscribe from this group, send email to
> materials-welding+unsubscribe@googlegroups.com
> For more options, visit this group's bolg at
> http://materials-welding.blogspot.com/
> 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.
>


--
With Regards...

♠ Ramesh D ♠
Ph: +919677185585.

--
To post to this group, send email to materials-welding@googlegroups.com
To unsubscribe from this group, send email to materials-welding+unsubscribe@googlegroups.com
For more options, visit this group's bolg at http://materials-welding.blogspot.com/
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.

No comments:

Re: [MW:34832] Inquiry about Single Bevel with Back Grinding

Dear Uday, As per your question that one is called with backing only,Simple both side you are welding it is backing with strip or without st...