Dear Venky,
As you can see the details provided by Raghvendra at first hand, where the second shell (having done PWHT without acid pickling and pasivation) does not have this defects.
Mean this is nothing to do with differntial expansion, joint design, bead sequence and parameters.
I have came accros the case where full surface was forroded after pickling and passivation and the reason was the same as explained in my earlier mail.
--
C. K. Purohit
Eng-Tech Weld1
Sr Welding Inspector
As you can see the details provided by Raghvendra at first hand, where the second shell (having done PWHT without acid pickling and pasivation) does not have this defects.
Mean this is nothing to do with differntial expansion, joint design, bead sequence and parameters.
I have came accros the case where full surface was forroded after pickling and passivation and the reason was the same as explained in my earlier mail.
2010/1/13 <fmajdnia@technip.com>
Here is the reply by our specialist :
"Usual problem (had personally faced) encountered while using Inconel
Overlay for SS 410S Clad. That too with P4 as the Base Material.
The issue is not due to Pickling or passivation rather due to the:
1) Differential thermal expansions between P4 base , SS 410S Clad and Clad
restoration by Inconel 625-
We can't do anything on this except to ensure the following :
a) During the clad restoration, the chamfering of the clad i.e 45° and
width of the clad restoration shall
be carefully considered.
b) Usually the corner pass between the Base & Clad shall be preferably
done by GTAW or low dia electrode
to get full fusion at the junction. If the fusion is in doubt , it will
open up during the subsequent passes/
layers of overlay and after PWHT also.
2) Here, the wagon track indication, is clearly associated with joint
design , bead sequence and Process parameters.
Lastly we need to know what was the PWHT Parameters used. This is very
important as we have different materials involved."
Regards
Principal Inspection Engineer- Welding/Metallurgy
Venkateshwaran Subramaniyam (Venky)
-----Fereidoun Majdnia/TPGAUH wrote: -----
----- Forwarded by Fereidoun Majdnia/TPGAUH on 01/12/2010 08:20 AM -----
Sent by: materials-welding@googlegroups.com
01/12/2010 07:31 AM Please respond to
<materials-welding@googlegroups.com>
cc
Subject
[MW:4019] Linear Indications After Pickling and passivation and PWHT
One of the section ( shell to Shell) under went the above process and
Dear All,
I have a typical problem with my vendor who is manufacturing Coke drums for
us.
The stage of NDT including RT is such that we need to take RT before PWHT
and before overlay.
cleared. After that it was overlayed by AWS class Inconel E NiCrFe3Now durng APWHT stage, when we are performing PT and RT, surprisingly we
electrodes on base plates ( SA387 Gr.11 ClassII) with 410S cladding on
either side. Later the same was subjected to Pickling and passivation and
went for PWHT.
are getting two wagon track linear indications on either sides of weld toesabove juncture. As per our estimation, it could have happend due to
from inside ( on cladding side) which are exactly the border junction of
ENiCrFe3 inconel and 410S cladding of the shell plates.
It is having a depth of around 0.5mm and width also same.
Could any one explain the cause of formation of this indication at the
pickling and passivation. Since another shell with above processes ( exceptSave a tree...please don't print this e-mail unless you really need to.
pickling and passivation ) has not got any such indications.
Thanks for your time and efforts.
Regards,
Raghavendra
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.
Save a tree...please don't 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.
Save a tree...please don't print this e-mail unless you really need to.
Save a tree...please don't print this e-mail unless you really need to.
Save a tree...please don't print this e-mail unless you really need to.
This email and any attached files ("Message") may contain confidential and/or privileged information. It is intended solely for the addressee(s). If you receive this Message in error, inform the sender by reply email, delete the Message and destroy any printed copy.
Any unauthorized use, distribution, or copying of this Message or any part thereof is prohibited. Emails are susceptible to alteration. Neither Technip nor any of its affiliates shall be liable for the Message if altered or falsified nor shall they be liable for any damage caused by any virus that might be transmitted with this Message.
--
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.
--
C. K. Purohit
Eng-Tech Weld1
Sr Welding Inspector
No comments:
Post a Comment