power outage with my rod oven

[qcgirl]

I know this is probably a stupid question but I'm going to ask anyhow....... the 7018 rod that we use is heated at 120 degrees C in our huge shop rod oven, our power was down and I became worried about the rod. The power was down for about 4 hrs, and after 4 hrs I checked the temp in the oven and it said 82 degrees C. At this point should I be re conditioning it? Or is the min actually lower than the 120 degrees C that is recommended? Essentially I would like to know if I have a window with a min max or just a target heat with no play on either side. (Many people had said that it would probably stay warm for a long time and that it should be fine) Thank you for your time, knowledge, and comments.

 

[gtaw]

It depends on what your welding standard requires.

If you are workng to AWS D1.1 you are permitted to rebake the electrodes at high temperature for one hour. Refer to the code for actual details.

Best regards - Al

 

[Kiwi2671]

qcgirl,
SFA 5.1 lists typical temperatures for a Holding Oven for 7018 as 30 to 140 degrees above ambient temperature so if your ambient the day you lost power was 20 - 30 degrees you would still be fine.
Not sure how this recommendation works in Alaska ?
Regards,
Kiwi

 

[qcgirl]

Sorry, I just realized I didn't specify that I am in British Columbia Canada, but anyhow I did refer to my code books (CSA Z662 & ASME B31.3) and my welding procedure and all I could find was 7.5.2.4 "Basic covered electrodes, after removal from sealed containers, shall be stored in cabinets at temperatures at the 120 C TO 150 C range prior to use.Such electrodes that have been exposed to atmospheric conditions for more than one hour shall be re dried prior to use in accordance with the manufacturer's specs" I couldn't seem to get a hold of anyone at Air Liquide being a Saturday, so I thought maybe I could get a quick answer on here. According to the second reply I would be good I think........the temp outside doesn't matter because they didn't come out of the oven and my rod oven only got down to 82 degrees C .......??? But like the first response, I was concerned about the fact that even though they weren't out of the oven they still had dropped too low and would need to be re conditioned for 4 hours. At what temp is the rod deemed unusable eg 119 deg C???I'm still very confused with the 2 different answers... I just hope I made the right call by listening to everyone else in my department, and I will keep trying to get ahold of Air Liquide to get the specs and hopefully it will be more specific.

 

[Ron]

The key is that the electrodes were not exposed to "atmospheric conditions", meaning the thermal and moisture conditions outside the oven.

E7018 electrodes are to be kept from moisture accumulation. Next time this happens, check the humidity in oven as well as the temperature so that you can logically rationalize a simple reheat rather than reconditioning.

 

[gtaw]

Does CSA Z662 have provisions to rebake the low hydrogen electrodes?

D1.1 allows the contractor to rebake the electrodes once provided they haven't actually been wet. I don't have the code in front of me, but I believe E7018 electrode have to be rebaked for an hour at 500 degrees F.

Rebaking is not the same as reconditioning.

Best regards - Al

 

[wegm]

You could also have a look at this link:

http://www.weldinguide.com/viewtopic.php?f=2&t=354

 

[wegm]

Sorry, the above link doesn't work, you could have a look at this link:

http://www.weldinguide.com/gdanastasiadis/viewtopic.php?f=2&t=354