Re: [MW:12376] SMAW ELECTRODE FOR P91 MATERIAL

The best choice of the three would be to use 9015-B9, as the others have chances of inclusion
of Sn, Sb, As, P etc as "tramp elements". These elements shall migrate to the grain boundaries
during welding and remain there after welding. These will affect grain bonding, subsequently
decreasing the creep resistance which shall show enhanced effects during high temperature
service leading to premature HAZ failure.
It is also strongly recommended to use non synthetic type electrodes i.e. core wire shall be of
same or equivalent composition of parent metal. Synthetic electrodes use a carbon steel core
wire and alloying elements are added to the flux coating. During welding these alloying
elements are infused into the weld, so that you do get the requisite weld metal chemistry but
the tramp elements are also included in the weld.
Himangshu












On Thu, 08 Sep 2011 10:02:42 +0530 wrote
>Dear Group Members,



I am having 3 approved WPSs for P91 material.These 3 WPS are using 3

different electrodes.



1)9018-B9 -Iron powder & Low hydrogen potassium coated

2)9016-B9 -Low hydrogen potassium flux coated

3)9015-B9 - Low hydrogen sodium flux coated



My doubts are



1)How we can justify which electrode is better for my use?

2)Any where in code it mentioned the suitable flux coating for

electrode?





Regards



Jose Sebastian

+919687660525



--

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.


Treat yourself at a restaurant, spa, resort and much more with Rediff Deal ho jaye!

--
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.