Preheat & Interpass temperature - Reg

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Ramesh Deenathayalan

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Jan 20, 2012, 2:40:10 AM1/20/12
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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

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John Henning

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Jan 20, 2012, 10:42:04 AM1/20/12
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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

Dear friends,

Ramesh D

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james gerald

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Jan 21, 2012, 7:03:33 AM1/21/12
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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 <jhen...@deltak.com>
To: material...@googlegroups.com
Sent: Friday, January 20, 2012 9:12 PM
Subject: [MW:13527] RE: 13526] Preheat & Interpass temperature - Reg
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Ramesh Deenathayalan

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Jan 23, 2012, 3:28:13 AM1/23/12
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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 <gerr...@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
>
>

> ________________________________

> materials-weld...@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.
>
> --
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> To unsubscribe from this group, send email to

> materials-weld...@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.
>
> --
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> To unsubscribe from this group, send email to

> materials-weld...@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.
>


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With Regards...

♠ Ramesh D ♠
Ph: +919677185585.

james gerald

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Jan 24, 2012, 1:49:23 AM1/24/12
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Refer Section 3 "PreQualified WPS" in AWS D1.1 in Material Grouping Table which gives Preheat and Interpass temperature for various structural grades of steels.

Also refer Appendix on Preheating in AWS D1.1
 
Thanks & Regards J.Gerald Jayakumar 0091-9344954677

From: Ramesh Deenathayalan <dayal....@gmail.com>
To: material...@googlegroups.com
Sent: Monday, January 23, 2012 1:58 PM
Subject: Re: [MW:13548] RE: 13526] Preheat & Interpass temperature - Reg
> materials-welding+unsub...@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 material...@googlegroups.com
> To unsubscribe from this group, send email to
> materials-welding+unsub...@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 material...@googlegroups.com
> To unsubscribe from this group, send email to
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> 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.
>


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With Regards...

♠ Ramesh D ♠
Ph: +919677185585.

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