I do not remember seeing any where in the Codes, but some specifications do mention aboout this.
Also this will remain aa a properiatry item of some good fabricators.
Thanks & Regards
J.Gerald Jayakumar0091-9344954677 -- 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.
From: Nalla Gane <gane2478@hotmail.sg>
To: materials-welding@googlegroups.com
Sent: Saturday, February 18, 2012 3:10 PM
Subject: RE: [MW:13732] RE: 13484] Pre-heating for cutting
To: materials-welding@googlegroups.com
Sent: Saturday, February 18, 2012 3:10 PM
Subject: RE: [MW:13732] RE: 13484] Pre-heating for cutting
Dear Gerald Yes, it is often recommended as good workmanship practices but is there anyware in Codes required as mandatory requirement? Thanks Ganesan
Date: Wed, 18 Jan 2012 04:18:53 -0800From: gerry_tup@yahoo.comSubject: Re: [MW:13501] RE: 13484] Pre-heating for cuttingTo: materials-welding@googlegroups.com
-- To post to this group, send email to materials-welding@googlegroups.comTo unsubscribe from this group, send email to materials-welding+unsubscribe@googlegroups.comFor 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.
For carbon steels upto certain thickness it is not required.
Only when the thickness is very high and for Chrome-moly steels it is recommended to preheat the base material before cutting to avoid formation of undesirable phases which leads to cracking. Preheating before cutting will result in grain coarsening and impair the Impact properties.
Moreover it is always recommended to grind the HAZ of the Gas cut surfaces.
Thanks & Regards
J.Gerald Jayakumar0091-9344954677 To post to this group, send email to materials-welding@googlegroups.comTo unsubscribe from this group, send email to materials-welding+unsubscribe@googlegroups.comFor 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.
From: DEBASISH <debasish.uae@gmail.com>
To: materials-welding@googlegroups.com
Sent: Wednesday, January 18, 2012 1:08 PM
Subject: Re: [MW:13500] RE: 13484] Pre-heating for cutting
To: materials-welding@googlegroups.com
Sent: Wednesday, January 18, 2012 1:08 PM
Subject: Re: [MW:13500] RE: 13484] Pre-heating for cutting
Perfect. To add more on this:
Basically this becomes more and more stringent, in case of low temp. steels, wherein the grain coarsening is detrimental to it's Impact ( Toughness ) properties. Also, Preheating before flame cutting is required to decrease the thermal gradient which eventually decreases the chances of grain coarsening & also reduces thermal shock or any initiation of micro fissuries leading to cracks latter. Workshop remedy is: we ask to remove the HAZ formed by flame cutting, by grinding the skin of the flame cut edge preparation. Offcourse, This stringent practice is generally not required for general Mild steels grades of steel.
regars,
DEBASISH
Dubai
+971504349936.
On Tue, Jan 17, 2012 at 2:35 PM, sandeep monody <smv.monody@gmail.com> wrote:
Dear all,The purposes of preheat are to avoid crack due to sudden heating and for wide heat affected zone,so in my openion preheating is required for both cutting and welding.Regards,Sandeep.M.V
On Tue, Jan 17, 2012 at 10:31 AM, Lakshman Kumar.B <lakshmankumar4@gmail.com> wrote:
Sent: Monday, January 16, 2012 3:22 PMTo: materials-welding@googlegroups.com Subject: [MW:13484] Pre-heating for cutting Dear Experts,I need your help for this subject, We are fabricating some piping as per B31.3, the material ASTM A106 Gr.B, 8"Sch-XXS and 160 and we are doing preheat and PWHT for welding, but my enquiry pre heat is required for cutting also? It is mentioned in any code or any other were? Please help meJesti--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.
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