New oven

[cnccutter]

Had a good year last year so at Christmas I ordered a EvenHeat KO18 with Tap controls. Took a little while to get it made, shipped, and installed but it's now all ready to go in my shop.

Last night I got to run my first batch of 440c through and man it this oven a rocket! The Tap controls worked great and seemed to keep the temp even as it went up. I got the 220 version so didn't take long to fire. Total time was 1 hour 25 minute with the soak times included. Blades came out of heat treat at a good R62 with a plate quench. Don't miss the mess of the oil at all! Will temper them this morning down to a 60ish.
Can't say enough good things about my new oven.

Erik

[jimmontg]

Envious. Nice sized oven. Did you cryo them or just leave out overnight without a temper? Just wondering as my 440C instructions always said temper immediately. We used an old cooking stove with a precise thermometer laser reader to know exactly how hot the oven was when we pre-heated it. Or we just put the blades in dry ice if we had to do a hotter temper than the stove was capable of. Should say machine parts as we never did any cutting blades with 1000 degree tempers excep thick D2 where it was called out on the blueprint specs. What it was supposed to do beside stabilize the dimensional size I don't know as they had to go to the grinder dept after I straightened them.

I never did much 440C as we seldom had it, but I had an 1/8" bar at home I had bought and I made a few knives from it. Mostly made knives from O1 and D2 and some AEB-L drop offs.

[cnccutter]

Jim I didn't cryo the blades this time. Not set up for that yet. I am tempering them as we speak. I would have rather tempered them last night but couldn't get the oven to cool enough for that so had to chance the wait. This is the first time for 440c for me so will be testing the blades and breaking one for grain size. It's all part of the learning curve.

Erik

[jimmontg]

I understand Erik, but you can use your house stove to temper immediately, those oven thermometers you can buy are fairly cheap and very accurate. We were a machine shop and it's what we used, boss brought his old oven from home one day and we had an electric tempering oven. Never trusted it until we got the temp gage though. There's toaster ovens too, but they are unreliable.

I'm not an expert on 440C but I would never leave O1 or D2 sitting all night without at the least putting them in the freezer between 2 pieces of dry ice at home. Not cryo'd, but will not crack before temper in morning, but maybe 440C is ok to leave overnight. Some others could weigh in here. Maybe just putting them in your freezer is OK. I remember reading about guys that did that back in the 90s until they could temper them.

To cryo with dry ice you need a thick ice chest (4" thick styrofoam) and leave it in there for 3 days minimum and still not as good as liquid nitrogen. Just a whole lot cheaper, but it does give the blades added toughness which means you can temper them to a higher hardness. RC60 is 10x harder than RC59. With a beautiful oven like your's I would do the best I could afford to be better at it. AEB-L needs a dry ice cryo , but doesn't need to soak, just drop to -95F.(dry ice is -109F) Seems like an easy steel to treat. RC 60 all day with toughness and cheaper than 440C.
Most of my HT experience is D2 and O1, with a few other types here and there like the AEB-L and 440C, plus some weird cobalt steel and aluminum and brass thrown in.

[Porard]

I just needed it. By the way, can someone here help me? I do some repairs in my kitchen and want some advice.