Hi
During PWHT when steel is heated below the A1 transformation temperature i.e 723 degree C, dislocation takes place,carbon is released from nucleated areas which allows the structure to deform plastically and relieve its internal stresses. There is no phase transformation below A1. It reduces hardness, tensile strength and increases toughness.
However crossing A1 temp. may result in very large / coarse grains, softer structure and poor toughness.
Hope this clarifies this issue.
Regards
Prem Nautiyal
Cell:9820313278
Mumbai.
On Tue, 09 Mar 2010 14:01:24 +0530 wrote
>
Remaining austenite, larger grain size
Dr. G. Dilintas
I&F Regional Technical Manager
Bureau Veritas Piraeus - Greece
Tel: +30 210 40 63 113/4
Fax: +30 210 40 63 118
"Girish Shejale"
"Girish Shejale"
Sent by: materials-welding@googlegroups.com
08/03/2010 09:20
Please respond to
materials-welding@googlegroups.com
To
cc
Subject
RE: [MW:4484] Why maximum PWHT temp shall be at least 20 °C less than tempering temp.
Ref
What kind of microstructural transformations are expected here?
Regards,
Girish Shejale
-----Original Message-----
From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com]On Behalf Of george.dilintas@gr.bureauveritas.com
Sent: Monday, March 08, 2010 10:26 AM
To: materials-welding
Subject: Re: [MW:4473] Why maximum PWHT temp shall be at least 20 °C less than tempering temp.
The pwht temperature must be lower than the lower transformation temperature in order to avoid microstructure alterations.
From: "Pradip Patil" [pradipp@godrej.com]
Sent: 08/03/2010 11:40 ZE5B
To:
Subject: [MW:4472] Why maximum PWHT temp shall be at least 20°C less than tempering temp.
Dear Sir,
Why maximum PWHT temp for CS and Low alloy steel materials shall be at least 20°C less than tempering temp?
With Regards,
Pradip Patil.
============================================================================================
This message (including any attachments) contains confidential information and is intended solely for the use of the individual or entity to whom they are addressed. If you are not the intended recipient you are notified that disclosing, copying, distributing or taking any action based on the contents of this information is strictly prohibited. If you have received this email in error please notify mailadm@godrej.com. Please note that any views or opinions presented in this email are solely those of the author and do not necessarily represent those of Godrej & Boyce Mfg. Co. Ltd. group of companies. The recipient should check this email and any attachments for the presence of viruses. Godrej & Boyce Mfg. Co. Ltd. group of companies accepts no liability for any damage caused by any virus transmitted by this email.
Please do not print this e-mail unless you really need to.
============================================================================================
--
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.
The information contained in this e-mail and any attachments is strictly confidential and is intended for the addressee only. Access to this e-mail by any other person is unauthorised. If you are not the intended recipient please destroy this message, delete any copies held on your systems and notify the originator immediately by reply e-mail. The unauthorised use, disclosure, alteration, copying, distribution or any action taken or omitted to be taken in reliance of this e-mail is strictly prohibited and may be unlawful. Opinions and views expressed in this e-mail are those of the sender. They may not reflect the opinions of MJB International / Masaood John Brown Limited and shall be understood as being neither given nor endorsed by it.
--
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.
>
PREM S NAUTIYAL
CELL : 9820313278
 |
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.
Comments