| Slight intermittent undercut permitted provided it does not form a sharp notch; depth should not exceed @4 mm WITH WARM REGARDS
ANKIT GUPTA
Er@BHEL--- On Wed, 10/28/09, Arjan van Vessum <vess_kiwi26@hotmail.com> wrote:
From: Arjan van Vessum <vess_kiwi26@hotmail.com>
Subject: [MW:3563] Re: acceptance crerteria of undercut
To: materials-welding@googlegroups.com
Date: Wednesday, October 28, 2009, 4:46 PM
Whats the wall tickness??? For criteria class C, check if h ≤0,1 t but max 0,5 mm...If weld length is appr 100mm a 25mm discontinuity is allowed as per section 3.3 (EN ISO 5817) greets, Arjan van Vessum
Subject: [MW:3556] acceptance crerteria of undercut Date: Wed, 28 Oct 2009 08:29:49 +0330 From: Samimi@mapnagenerator.com To: materials-welding@googlegroups.com Please let me know that according to iso 5817 rev: 2005 class C the undercut with 0.2mm depth and 24 mm length in Butt Weld and 100 mm length of our product is acceptable or not.if yes or no please explain exactly with detail. Best regards Alireza Samimi
__________ Information from ESET NOD32 Antivirus, version of virus signature database 4530 (20091021) __________
The message was checked by ESET NOD32 Antivirus.
http://www.eset.com
--~--~---------~--~----~------------~-------~--~----~
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.
-~----------~----~----~----~------~----~------~--~---
Whats the wall tickness??? For criteria class C, check if h ≤0,1 t but max 0,5 mm... If weld length is appr 100mm a 25mm discontinuity is allowed as per section 3.3 (EN ISO 5817) greets, Arjan van Vessum
Subject: [MW:3556] acceptance crerteria of undercut Date: Wed, 28 Oct 2009 08:29:49 +0330 From: Samimi@mapnagenerator.com To: materials-welding@googlegroups.com Hi dear Please let me know that according to iso 5817 rev: 2005 class C the undercut with 0.2mm depth and 24 mm length in Butt Weld and 100 mm length of our product is acceptable or not.if yes or no please explain exactly with detail. Best regards Alireza Samimi __________ Information from ESET NOD32 Antivirus, version of virus signature database 4530 (20091021) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com --~--~---------~--~----~------------~-------~--~----~ 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. -~----------~----~----~----~------~----~------~--~---
First idea is to use CrMo2 consumables (or CrMo1 could be solution too, depending on application / requirements) Preheat 200 degrC PWHT at 690 °C , however · PWHT temperature is depending on strength requirements 4130 and required charpy values in weld metal · duration is depending on wall thickness and required charpy values in weld metal Stick electrodes · OERLIKON CROMOCORD 2 STC · OERLIKON OE KV3 HR TIG rod: · OERLKON CARBOROD CrMo2 or · OERLIKON CARBOROD KV3 (=B2) Erwin Gering AIR LIQUIDE WELDING 
Van: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] Namens rajagopal kannan
Verzonden: woensdag 28 oktober 2009 8:23
Aan: materials-welding@googlegroups.com
Onderwerp: [MW:3559] CONSUMABLES Could you please suggest me the apt consumable for GTAW and SMAW to weld SA 182 Gr. F22 cl.1 with AISI 4130?
--~--~---------~--~----~------------~-------~--~----~ 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 following are authorized for PED qualification issue: 1.Lloyd's regirstrar 2. TWI ( TWI in malaysia being nearer to your place, you can contact them) 3.TUV-nord,Germany etc.., Thanks ! Larsen & Toubro Limited
www.larsentoubro.com This Email may contain confidential or privileged information for the intended recipient (s) If you are not the intended recipient, please do not use or disseminate the information, notify the sender and delete it from your system.
>>> "Tran Van Vuong" <vuong.tv@gmail.com> 28/10/2009 12:45 pm >>>
Dear,
We are operating in NDT. Our service qualified according to SNT-TC-1A. Now we are finding The Body as Recognized Third Party Organizations (RTPO)
for qualification in PED projects. Please let me know some this organization. Best regards, TRAN VAN VUONG Deputy Technical Director HP +84 912 262 085 Email: vuongtv@phateco.com ------------------------------------------- PHATECO Pha Rung Technical Services JSC. Inspection Services Add: 308 Van Cao Str., Haiphong City, Vietnam Tel: +84 31 6 260 254 Fax: +84 31 3 559 448 Email: <mailto:admin@phateco.com> admin@phateco.com Website: <http://www.phateco.com> www.phateco.com
--~--~---------~--~----~------------~-------~--~----~
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.
-~----------~----~----~----~------~----~------~--~---
Dear Mr.Devang Naik What is meant by hot MT ? Is it possible for Austenitic Stainless Steels ? Regards Prem Nautiyal Godrej,Mumbai Cell:9820313278 On Tue, 27 Oct 2009 20:49:24 +0530 wrote >Dear Mr. Syed and Mr. Prem > > You may go for hot MT after root pass. > > Thanks > > Devang Naik > > On Tue, 27 Oct 2009 11:22:17 +0530 wrote > > > > > Hello Syed > > > > > > You can very well conduct PT after Root pass while welding SS, only ensure that temp. has come below 52 degreeC. > > > We regularly conduct PT after root pass when welding SS jobs even upto 70mm thick with GTAW. > > > > > > The chances of cracking after GTAW root pass is seen in thick sections of CS and LAS material i.e above 20/25mm thick OR having high restraints. Hence while welding such materials,we conduct PT after hot pass only. > > > For thin sections LPT can be done safely after root pass for CS/LAS material. > > > This is only my experience which i would like to share with you!! > > > > > > Regards > > > > > > Prem Nautiyal > > > Godrej, Mumbai > > > Cell:9820313278 > > > > > > On Sun, 25 Oct 2009 17:12:07 +0530 wrote > > > >Recently I faced the following issue and kindly clarify my doubt. A qualified WPS for stainless steel (A312-TP304H) requires PT after root pass. After root pass, its not possible to perform PT immediately unless the temperature reduces. > > > But, in normal practice,any weld is not to be stopped before completing hot pass or 1/3rd of groove thickness. I got difficulty in following both conditions on single weld joint. > > > Based on the above different opinions, kindly suggest me the right one with details. > > > > > > PREM S NAUTIYAL > > > CELL : 9820313278 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.
-~----------~----~----~----~------~----~------~--~---
Dear Members, Could you please suggest me the apt consumable for GTAW and SMAW to weld SA 182 Gr. F22 cl.1 with AISI 4130? Thanks and Best Regards, K.Rajagopal --~--~---------~--~----~------------~-------~--~----~ 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. -~----------~----~----~----~------~----~------~--~---
Dear, We are operating in NDT. Our service qualified according to SNT-TC-1A. Now we are finding The Body as Recognized Third Party Organizations (RTPO) for qualification in PED projects. Please let me know some this organization. Best regards, TRAN VAN VUONG Deputy Technical Director HP +84 912 262 085 Email: vuongtv@phateco.com ------------------------------------------- PHATECO Pha Rung Technical Services JSC. Inspection Services Add: 308 Van Cao Str., Haiphong City, Vietnam Tel: +84 31 6 260 254 Fax: +84 31 3 559 448 Email: admin@phateco.com --~--~---------~--~----~------------~-------~--~----~ 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. -~----------~----~----~----~------~----~------~--~---
these are used in many ways to connect FRP flanges, or even reducing fillers, mostly in utility lines, may get some info AWWA The PTFE Filler Flanges are used to connect flanges with raised faces
or sealing surfaces-especially those of plastic lined steel pipe-to
flat faced plastic flanges. Without filler flanges, when the bolts are
tightened on such a joint, the plastic flange will, most likely,
break. The filler flange fills the gap that lies between the OD of the
raised surface and the OD of the flange, flattening the face in
contact with the plastic flange. Reducing Flange Fillers can be furnished for connecting pipe of two
different diameters. In such cases, the fillers have two sets of bolt
holes with one or both sets of holes tapped for studs. On Oct 28, 8:43 am, "Bagesh" <bagesh....@gmail.com> wrote:
> Recently while going through a project document of our project, I found a
> term named "FILLER FLANGE". I would like to know the constructability and
> its usage in Piping terms.
>
> I would like to put the same on the discussion topic so that I along with
> the unknown members can go through it. I have heard its usage is for
> connecting Flat face flanges with Raised Face Flanges.
>
> Thanking You.
>
> Bagesh Kumar.
--~--~---------~--~----~------------~-------~--~----~
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.
-~----------~----~----~----~------~----~------~--~---
Hi dear Please let me know that according to iso 5817 rev: 2005 class C the undercut with 0.2mm depth and 24 mm length in Butt Weld and 100 mm length of our product is acceptable or not.if yes or no please explain exactly with detail. Best regards Alireza Samimi __________ Information from ESET NOD32 Antivirus, version of virus signature database 4530 (20091021) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com --~--~---------~--~----~------------~-------~--~----~ 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. -~----------~----~----~----~------~----~------~--~---
Recently while going through a project document of our project, I found a term named “FILLER FLANGE”. I would like to know the constructability and its usage in Piping terms. I would like to put the same on the discussion topic so that I along with the unknown members can go through it. I have heard its usage is for connecting Flat face flanges with Raised Face Flanges. Thanking You. Bagesh Kumar. --~--~---------~--~----~------------~-------~--~----~ 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. -~----------~----~----~----~------~----~------~--~---
Dear all, Thanks for the replies. I am trying to recommend them to use Avesta 248 SV rutile electrode
www.avestawelding.com/3206.epibrw
Which I have it on our stock.
I see that the chemicals composition and mechanical properties is only
have a little bit different, while this type of electrode not comply
to AWS E630 @ Prem : I interest to your WPS when you apply E308L for your case,
please send me directly a copy of it. Thanks for cooperation. Best regards,
Maringan On 10/27/09, PREM SHANKARDUTT NAUTIYAL <prem_nautiyal@rediffmail.com> wrote:
>
> Hi
>
> We weld 17-4PH with E308L electrodes for SMAW process.
> I will send you the complete welding procedure tomorrow if you require..
>
> Regards
>
> Prem Nautiyal
> Cell:9820313278
>
> On Tue, 27 Oct 2009 18:01:48 +0530 wrote
>>Sir
> If 17-4PH is it pre trated to any specfic condition as like 950, 1075 or
> 1100, 1150 ?
> If pre trated , then it would be best to use 312 type electrode
> Regards
> Suneel Gore
>>
>>--- On Tue, 27/10/09, Maringan Hutagalung wrote:
>>
>
>>From: Maringan Hutagalung
>>Subject: [MW:3549] Electrode for 17-4 PH cast steel
>>To: materials-welding@googlegroups.com
>>Date: Tuesday, 27 October, 2009, 12:32 PM
>>
>>
>
>>Dear all,
>>
>>Our customer as a pulp and paper mill service are repairing
>>a liner in a rotor housing, the material is a cast steel type 17-4PH.
>>
>>For repair of some defect caused corrosion and abrasion wear, they
>>require an electrode AWS E630.
>>
>>Does anyone can give an advice for other type of electrode to
>>substitute a E630 since
>>we don't have stock of it.
>>
>>Thanks in advance
>>
>>
>>Maringan
>>
>>--
>>Sent from my mobile device
>>
>> From cricket scores to your friends. Try the Yahoo! India Homepage!
>
> PREM S NAUTIYAL
> CELL : 9820313278
> >
> --
Sent from my mobile device --~--~---------~--~----~------------~-------~--~----~
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.
-~----------~----~----~----~------~----~------~--~---
Hi We weld 17-4PH with E308L electrodes for SMAW process. I will send you the complete welding procedure tomorrow if you require.. Regards Prem Nautiyal Cell:9820313278 On Tue, 27 Oct 2009 18:01:48 +0530 wrote >Sir If 17-4PH is it pre trated to any specfic condition as like 950, 1075 or 1100, 1150 ? If pre trated , then it would be best to use 312 type electrode Regards Suneel Gore > >--- On Tue, 27/10/09, Maringan Hutagalung wrote:
>
>From: Maringan Hutagalung
>Subject: [MW:3549] Electrode for 17-4 PH cast steel
>To: materials-welding@googlegroups.com
>Date: Tuesday, 27 October, 2009, 12:32 PM
>
>
>Dear all,
>
>Our customer as a pulp and paper mill service are repairing
>a liner in a rotor housing, the material is a cast steel type 17-4PH.
>
>For repair of some defect caused corrosion and abrasion wear, they
>require an electrode AWS E630.
>
>Does anyone can give an advice for other type of electrode to
>substitute a E630 since
>we don't have stock of it.
>
>Thanks in advance
>
>
>Maringan
>
>--
>Sent from my mobile device
>
> From cricket scores to your friends. Try the Yahoo! India Homepage!
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.
-~----------~----~----~----~------~----~------~--~---
Sir If 17-4PH is it pre trated to any specfic condition as like 950, 1075 or 1100, 1150 ? If pre trated , then it would be best to use 312 type electrode Regards Suneel Gore
--- On Tue, 27/10/09, Maringan Hutagalung <maringan.hutagalung@gmail.com> wrote:
From: Maringan Hutagalung <maringan.hutagalung@gmail.com>
Subject: [MW:3549] Electrode for 17-4 PH cast steel
To: materials-welding@googlegroups.com
Date: Tuesday, 27 October, 2009, 12:32 PM
Dear all, Maintaining interpass temperature is up to the WPS preparing authority. You can stop very well at root pass, cool down and carry on PT. This shall be established in WPS / PQR enabling to follow the same during production welding. Regards, R.Gopalasamy, Sr.QA/QC Consultant, Hindustan Oil Exploration Company Ltd, PY1, Onshore Gas Processing Facility, Thirukkadaiyur. email : rgopalasamy @hoec.com Mobile : 09789090752 -------------------------------------------------------------------- HOEC Email Disclaimer : http://www.hoec.com/email_disclaimer.htm
From: materials-welding@googlegroups.com on behalf of PREM SHANKARDUTT NAUTIYAL
Sent: Mon 10/26/2009 7:40 PM
To: smmubarakqc@gmail.com
Cc: materials-welding@googlegroups.com
Subject: [MW:3547] Re: PT after root pass in SS welding
Hello Syed You can very well conduct PT after Root pass while welding SS, only ensure that temp. has come below 52 degreeC. We regularly conduct PT after root pass when welding SS jobs even upto 70mm thick with GTAW. The chances of cracking after GTAW root pass is seen in thick sections of CS and LAS material i.e above 20/25mm thick OR having high restraints. Hence while welding such materials,we conduct PT after hot pass only. For thin sections LPT can be done safely after root pass for CS/LAS material. This is only my experience which i would like to share with you!! Regards Prem Nautiyal Godrej, Mumbai Cell:9820313278 On Sun, 25 Oct 2009 17:12:07 +0530 wrote >Recently I faced the following issue and kindly clarify my doubt. A qualified WPS for stainless steel (A312-TP304H) requires PT after root pass. After root pass, its not possible to perform PT immediately unless the temperature reduces. But, in normal practice,any weld is not to be stopped before completing hot pass or 1/3rd of groove thickness. I got difficulty in following both conditions on single weld joint. Based on the above different opinions, kindly suggest me the right one with details. 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.
-~----------~----~----~----~------~----~------~--~---
Dear Maringan, If you have stock of 25/12 electrode you can use of it. It is a superior electrode but costlier than the E630. Muniyandi On Tue, Oct 27, 2009 at 12:32 PM, Maringan Hutagalung <maringan.hutagalung@gmail.com> wrote:
Dear all,
Our customer as a pulp and paper mill service are repairing
a liner in a rotor housing, the material is a cast steel type 17-4PH.
For repair of some defect caused corrosion and abrasion wear, they
require an electrode AWS E630.
Does anyone can give an advice for other type of electrode to
substitute a E630 since
we don't have stock of it.
Thanks in advance
Maringan
--
Sent from my mobile device
--~--~---------~--~----~------------~-------~--~----~ 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. -~----------~----~----~----~------~----~------~--~---
Dear all, Our customer as a pulp and paper mill service are repairing
a liner in a rotor housing, the material is a cast steel type 17-4PH. For repair of some defect caused corrosion and abrasion wear, they
require an electrode AWS E630. Does anyone can give an advice for other type of electrode to
substitute a E630 since
we don't have stock of it. Thanks in advance
Maringan
--
Sent from my mobile device --~--~---------~--~----~------------~-------~--~----~
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.
-~----------~----~----~----~------~----~------~--~---
dear group members, why heat treated astm pipe is preferred than non heat treated api 5l pipes. regards dinesh | --~--~---------~--~----~------------~-------~--~----~
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.
-~----------~----~----~----~------~----~------~--~---
Hello Syed You can very well conduct PT after Root pass while welding SS, only ensure that temp. has come below 52 degreeC. We regularly conduct PT after root pass when welding SS jobs even upto 70mm thick with GTAW. The chances of cracking after GTAW root pass is seen in thick sections of CS and LAS material i.e above 20/25mm thick OR having high restraints. Hence while welding such materials,we conduct PT after hot pass only. For thin sections LPT can be done safely after root pass for CS/LAS material. This is only my experience which i would like to share with you!! Regards Prem Nautiyal Godrej, Mumbai Cell:9820313278 On Sun, 25 Oct 2009 17:12:07 +0530 wrote >Recently I faced the following issue and kindly clarify my doubt. A qualified WPS for stainless steel (A312-TP304H) requires PT after root pass. After root pass, its not possible to perform PT immediately unless the temperature reduces. But, in normal practice,any weld is not to be stopped before completing hot pass or 1/3rd of groove thickness. I got difficulty in following both conditions on single weld joint. Based on the above different opinions, kindly suggest me the right one with details. 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.
-~----------~----~----~----~------~----~------~--~---
Hi, Pre heating of weld joints is to remove the tensile residual stresses, due to welding and to homogenise the material. Particularly tensile residual stresses- If the tensile residual stress of the material exceeds more than 50 % of the yield stress of the material, it will lead to localised yielding/cracking. Regards, Vaidehi ganesan, Metallurgy and Materials Group, IGCAR, Kalpakkam-603 102, India. ============================================================================ ----- Original Message ----- From: "redbull" < mohanq8@gmail.com> To: "Materials & Welding" < materials-welding@googlegroups.com> Sent: Mon, Oct 26, 09 12:44 Subject: [MW:3544] Reason for preheating
>
> Dear friends,
>
> Is there any other reason for preheating of weld joints other than
> Code requirements (B31.3). any metallurgical requirement etc.,
>
> Regards,
>
> Mohan.
>
>
-------------------------------------------------------------------------------- No virus found in this incoming message.
Checked by AVG - www.avg.com
Version: 8.5.423 / Virus Database: 270.14.32/2459 - Release Date: 10/25/09
19:57:00
--~--~---------~--~----~------------~-------~--~----~
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.
-~----------~----~----~----~------~----~------~--~---
Pre Heating : To control the formation of H2 cracks. Control the effects of expansion & contractional stresses.
PREHEATING
What is Preheat?
Preheating involves heating the base metal, either in its entirety or just the region
surrounding the joint, to a specific desired temperature, called the preheat temperature, prior
to welding/cutting. Heating may be continued during the welding process, but frequently the
heat from welding is sufficient to maintain the desired temperature without a continuation
of the external heat source. The interpass temperature, defined as the temperature
between the first and last welding passes, can not fall below the preheat temperature.
Why Preheat?
There are four primary reasons to utilize preheat:
(1) it lowers the cooling rate in the weld metal and base metal, producing a more ductile
metallurgical structure with greater resistance to cracking;
(2) the slower cooling rate provides an opportunity for any hydrogen that may be
present to diffuse out harmlessly without causing cracking;
(3) it reduces the shrinkage stresses in the weld and adjacent base metal, which is especially
important in highly restrained joints and
(4) it raises some steels above the temperature at which brittle fracture would occur in
fabrication. Additionally, preheat can be used to help ensure specific mechanical properties,
such as notch toughness.
When Should Preheat be Used?
In determining whether or not to preheat, the following array of factors should be
considered: code requirements, section thickness, base metal chemistry, restraint, ambient
temperature, filler metal hydrogen content and previous cracking problems.
If a welding code must be followed, then the code generally will specify the minimum preheat
temperature for a given base metal, welding process and section thickness. When there are no
codes governing the welding, one must determine whether preheat is required, and if so,
what preheat temperature will be appropriate. In general, preheat usually is not required on
low carbon steels less than 1 in, (25 mm) thick. However, as the chemistry, diffusible
hydrogen level of the weld metal, restraint or section thickness increases, the demand for
preheat also increases. There are several methods to determine the required preheat
temperature for a given base metal and section thickness that will be discussed in the next
section.
Regards,
Rupesh A. Jambhale
Inspection Department,
Mott MacDonalds Consultants (India) Pvt Ltd., Mumbai
-----Original Message-----
From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of redbull
Sent: 26 October 2009 12:45
To: Materials & Welding
Subject: [MW:3544] Reason for preheating
Dear friends,
Is there any other reason for preheating of weld joints other than Code requirements (B31.3). any metallurgical requirement etc.,
Regards,
Mohan.
______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________ --~--~---------~--~----~------------~-------~--~----~ 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. -~----------~----~----~----~------~----~------~--~---
Any advice for cast iron welding Sent from Yahoo Mail for iPhone
-
Q: What are equivalents for standard Q 235 B (and Q 235 A) for U-channels? ...
-
Definition of buttering from ASME Section IX, QW/QB-492 Definitions: Buttering: the addition of material, by welding, on one or bot...
-
Section I. PRINT READING 3-1. GENERAL a. Drawings . Drawing or sketching is a universal language used to convey all necessary information to...
|
|
