Thursday, April 15, 2010

Re: [MW:4840] RE: 4827] cellulose electrodes.

On the consideration of diffusible hydrogen and cellulosic electrodes ie. E6010:
The lower mechanical values do occur in the "as-welded" condition. However, as the product ages (30-60 days), the diffusible hydrogen diffuses from the weld metal and the final "in-service" weld has mechanical properties very similar to the low-hydrogen ie. E7018 weld deposit.
 



On 2010-04-14, at 10:51, John Henning <jhenning@deltak.com> wrote:

The primary advantage to cellulose electrodes (EXX10 and EXX11) is that they form a thin slag cover and are what Lincoln electric called "fast freeze".  They produce a deeply penetrating arc but because of the thin slag, solidify rapidily.  Therefore they are very good at bridging gaps and were used for making root passes in piping/pipe lines.
 
The major disadvantage is that the cellulose, a hydrocarbon, breaks down in the heat of the arc and produces copious hydrogen which is absorbed into the molten weld pool.  These electrodes produce the highest weld metal hydrogen of all common practices/processes.  Therefore they may cause hydrogen assisted cracking if the other required factors are present.   
 
A minor disadvantage is that the weld is coarse in appearance due to the high solidification rate and therefore may lack visual appeal.
 
John


From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of prashant pansare
Sent: Wednesday, April 14, 2010 8:55 AM
To: mat wel
Subject: [MW:4827] cellulose electrodes.

Dear all,
What r advantages & dis-advantages of cellulose electrodes.
Pl. reply.
psp

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