Evenheat Oven Experience

M

Mike Mossington

Joined
Jan 1, 2004
Messages
108
Question for those who use an Evenheat - based on your experience, is it better to heat treat 1 blade per time (for example, 440C or ATS34) and plate quench, or to do several blades at once? Does it matter?

The only problem I see is that when doing more than 1 batch, it takes longer to get the plates down and may result in warpage?

If doing only 1 blade per, does the oven need to come right down in temperature, or can the next blade go in at, say, 1500 degrees, and then start the next cycle? Does this give long enough for the blade to come up to heat (and then soak for the recommended time, of course).

Appreciate your thoughts. Mike
 
i'm guessing if you're using stainless steel anything, you'd load the blanks in the SS Foil (all of them at once) and turn the kiln on and walk away till it was time to take them out. When the cycle is complete, depending on how wide your plates are, you could quench several at a time. I have done maybe 4 or 5 blades at a time just standing on the plates. The plates quickly suck the heat out of the blades and transfer to the plate itself, so after two quenches or so, the plates get hot being aluminum.

it all depends on how FAST you are at doing it will vary the results. If your stainless steel foil is thicker on the crimped edge the the actual blade say 1/16" thick, then sure that might cause a problem of warpage when you quench the blade. It's just something you're gonna have to try out and see what works best for you! Have fun!
 
Being frugal (cheap) I always do at least 5 blades per firing,just make sure they are all of the same thickness, ie 1/8" . not had a problem with warpage.
 
Doing multiples is fine, so long as you intend the same temperature for hardening all of them. You mentioned ATS4 and 440C and while they have a bit of overlap in possible temperatures, that overlap is not ideal for either.

You can do different thicknesses at the same time in the oven as well but only quench one thickness at a time. Yesterday, I had seven blades in at once. I quenched the four 1/8 thick ones first at 45 minutes - the two 5/32 blades about 5 minutes later and then the 3/16 blade.

I don't believe there is any metallurgical reason to take the oven down to cool between blades (or batches), but be aware that putting an envelope in high temperature causes rapid expansion and can lead to blown envelopes.

Rob!
 
I think the only time ever I had an envelope actually expand on me was when I put a piece of kraft paper in there that was possibly too large for the foil packet and maybe when the paper burned up, it caused excess gas to build up in the envelope? Out of 200+ blades that was the only one. Eventhough the envelope filled with gas or whatever that caused it to expand, the surface the blade was still scale free and looked the same as all the over knives in the batch. lol, that one I had to take out of the foil packet to quench it between the plates.

Pohan Leu
 
You must log in or register to reply here.
Back
Top