We have done that for valve parts before (balls mostly) and results were satisfactory...
What is the overlay thickness you require...?
If it is below 800 or even 1000 microns, metal spray will give you good results without any cracking...
Regards
Ramin Kondori 
QC/Welding Engineer
IWE AT 0070
On Tue, Aug 16, 2011 at 7:15 PM, Muni Andy <cmkfc07@gmail.com> wrote:
Dear friends,
In valve industry,Stellite 6 is successfully overlayed in WCB material in seat rings and wedges/discs
Preheat is must and slow cooling normally in lime powder immediately after deposit is followed.
Muniyandi..
On Tue, Aug 16, 2011 at 8:53 PM, John Henning <jhenning@deltak.com> wrote:Stellite is a registered trade mark of Deloro Stellite
This is personal experience from the my time in the electric power
industry - Stellite 6 typically is applied only in shop and not in the
field. Stellite 6 can be successfully welded when high levels of
preheat are applied. When welding Stellite 6, the entire assembly/item
should be uniformly heated to the preheat temperature and cooled slowly
after welding. When field welding, Stellite 21 is preferred as only
modest preheat is required and because Stellite 21 is more ductile, as
deposited, than Stellite 6. Stellite 21 will work harden to develop
full hardness. Stellite 6 will be harder than Stellite 21. I have seen
many valves refurbished in the field with Stellite 21 being replaced
with Stellite 6.
I have never heard of using Stellite 21 as an interlayer before welding
Stellite 6.
John
-----Original Message-----
From: materials-welding@googlegroups.com
[mailto:materials-welding@googlegroups.com] On Behalf Of Raghuram
Bathula
Sent: Monday, August 15, 2011 11:35 PM
To: materials-welding@googlegroups.com
Subject: Re: [MW:12229] Hairline cracks in stellite 6 coating (HF) -
A216 WCB
Any experience with barrier layer of Inconel or stellite 21 and then
with stellite 6?
On Mon, Aug 15, 2011 at 2:32 PM, tong tong <tong2je@gmail.com> wrote:
> Same with my situation. During our last TA, the stellite 6 was
overlaid on
> jet nozzle of regen. standpipe after minor repair on it. After the
weldment
> was cooling down, DPT was carried on that particular area and revealed
a
> hair line crack.
>
> On Fri, Aug 12, 2011 at 4:00 PM, Materials & Welding
> <materials-welding@googlegroups.com> wrote:
>>
>> Is it true that stellite 6 HF will leave hairline cracks on the
>> surfece?, one of the reputed valve vendor is quoitng that
>>
>> "Seat overlay made of Stellite 6 is possible but not recommended by
>> us. We clearly mention that it is not possible to perform a Stellite
6
>> completely free of hair cracks. Probably after final machining the
>> surface will show hair cracks which is normal in case of using
>> Stellite 6 and this do not affect the sealing functiont We normally
do
>> not use Stellite 6 because of this fine cracks and because of much
>> better experience with Stellite 21. If you insist on Stellite 6
>> seating surface showing hair cracks will not be a reason not to
accept
>> the valves if seat tightness test is ok"
--
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.
--
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.
No comments:
Post a Comment