Dear Jegan,
You are right that PWHT is the part of welding.
PWHT is generally done in 3 condition for steel 1. Below the Lower critical temp, 2. above the lower critical temp & below the upper critical temp and 3. above the upper critical temp.
Where as SR is the one kind of PWHT condition1 only for residual stress relieve.
Go through the Iron carbon equilibrium diagram & TTT diagram for detail of grain & microstructure.
On Fri, Sep 9, 2011 at 3:01 PM, Eswaran samikannu <eswaranaws@yahoo.co.in> wrote:
--Dear Experts Good Day to all,I want to Clarify Stress relieving & PWHT . In Industry and generally talking and refering the books both words are used interchangeably.My point of view stree relieving is applicable to the part which are undergone Hot/Cold working Examble like Dish Head,rolled products etc , PWHT is applicable to the welded part , Holding the temperature below the Tempering temperature to relieve stress to few hours depends on Code/End use requirements.Any one can explain temperature of stress relieving , PWHT and any terminology of this two.Any one can define the carbon Manganese steels & where we find the list of this materials, ABS Gr EH36 material fall in this catagory & If we fabricate EH36 material more than 50 mm thick full penetration weld followed AWS D1.1 code need to PWHT,Client nothing specified .Thanks in AdvanceBy JeganFrom: Karthik <karthik6684@yahoo.com>
To: materials-welding@googlegroups.com
Sent: Friday, 9 September 2011 4:17 PM
Subject: Re: [MW:12390] Need advise to clarrify client - Dish head stress relieving simulated PWHT test panel
-- 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.
--- On Fri, 9/9/11, murugesan jeyaraman <jmurugesan@gmail.com> wrote:
From: murugesan jeyaraman <jmurugesan@gmail.com>
Subject: [MW:12389] Need advise to clarrify client - Dish head stress relieving simulated PWHT test panel
To: materials-welding@googlegroups.com
Date: Friday, September 9, 2011, 2:29 PM
Dear FriendsPlease offer me your suggestion how we can settle the following case.We fabricated and supplied one pressure vessel to one of our client two years back. Now only they have reviewed our documents and come back with following observations.Code of construction is ASME VIII Div 1 and AS1210 and AS4458, Material SA 516 Gr 70, thickness 30 mm,Our vessel dish head is Stress relieved as per ASME viii Div 1 code requirement, but we have not done any simulated PWHT test panel for this stress relieve treatment.as per AS 4458, Unless any mechanical test is done to prove Stress relieved components are restored to their original material properties, normalising is the preferered heat treatment for cold formed components.It is obvious from above that either we have to do SR with Simulated PWHT test panel or Normalising of dished head.Actually we have overlooked AS 4458, so we have only done SR without PWHT test panels, so no mechanical testing was done.At this stage we cannot do normalising as plant is already running.At this stage, we do no have stock of same heat number plate.Please suggest how we can answer this observation.Can we say we have overlooked AS and SR done as per ASME Viii Div 1 as a normal practice in South east asia.We hve not done any Hardness test being carbon steel material.ThanksMurugesan-- 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.
To post to this group, send email to materials-welding@googlegroups.com
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--
Thanks & Regards
Biplab Pal
Industrial Services, Inspection Engineer.
SGS India Pvt. Ltd.
Kolkata Branch
Industrial Services, Inspection Engineer.
SGS India Pvt. Ltd.
Kolkata Branch
E-mail: biplab.mech@gmail.com
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Information in this email and any attachments is confidential and intended solely for the use of the individual(s) to whom it is addressed or otherwise directed. Please note that any views or opinions presented in this email are solely those of the author and do not necessarily represent those of the Company. Finally, the recipient should check this email and any attachments for the presence of viruses. Myself accepts no liability for any damage caused by any virus transmitted by this email.
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