Nitrogen Purge in HT furnace

W

winstonknives

Joined
Apr 24, 2001
Messages
788
I am thinking about introducing a nitrogen purge in my heat treat oven during hardening heat in place of using foil wrap. Does anyone have any info on this? Thanks
 
I don't think just purging it will help.You would have to maintain positive pressure of the gas in the furnace .They usually use argon, though I worked at a place that used hydrogen !!!!! ( yes boys and girls hydrogen and air form an explosive mixture ). If you want to do it right get a vacuum furnace.
 
If you have a Paragon oven then contact them. They have an oven with an argon purge type set up. I believe that they offer it as a retro fit kit also.
 
Bruce, I actually meant Nitrogen. Having been a pipefitter for over 30 years this is what came to mind. Nitrogen is used to purge stainless pipe while welding (even though argon is used in the welding process) to prevent scaling inside the pipe. It is also about 60% cheaper than argon. I am just trying to get away from foil if I can. Turco is out of the question. It just seemed to me if I could rid the oven of air and maintain a positive flow of Nitrogen during heat treat it might work. I am sure vacuum would be ideal but I am into saving $$$$ not spending it. I do use Turco on my damascus and it works extremely well. I can not figure why it went from $40/gal to $80/gal though. I guess they figured out knifemakers were using it. :D

Thanks
 
I have worked with equipment that had a natural gas flow into the covered pouring ladle to exclude oxygen. It vented and was burned off at the pouring spout.

About any non oxidizing gas will work as a purge if you can figure out what to do with it afterwards. The vented nitrogen will have to be removed from the area somehow to prevent buildup.
 
If not used outside or in a very well ventilated area constant nitrogen pressure could be harmful to life, I believe, from breathing it. Maybe that's why its always argon I see as the gas of choice.

RL
 
rlinger said:
If not used outside or in a very well ventilated area constant nitrogen pressure could be harmful to life, I believe, from breathing it. Maybe that's why its always argon I see as the gas of choice.

RL
Click to expand...

Hi Roger, don't want to breathe argon either. both are inert gasses and would work. We used nitrogen to purge our vacuum tube furnaces I used for pulsed laser deposition experiments back in grad school. I also used nitrogen positive pressure when changing out experimental set-ups in a large vacuum chamber I would use for field emission work. We used to pay something like $5 for those large 200 CF nitrogen cylinders....much cheaper than argon. :)

-Darren
 
remember too,
once you pull the blade out to quench it
you'll need to keep it from oxygen that's where you'll get most of the Scaling I believe anyway.
also a positive pressure from cool gas in a reg oven means a cooler oven .
+ more $ in electric..I have thought in the lines of CO2 but that is bad for electric elements
 
You must log in or register to reply here.
Back
Top