Oil quenching air hardening steels.

jmforge

jmforge

Well-Known Member
I have seen some folks like Roman Landis say that they oil quench air hardening steels. I am thinking about CPM 3V and maybe later some ALDO AEB-L equivalent. I have both AAA and 50 and I was wondering if you could quench it in 50 that had not been warmed up to perhaps make it a less violent clinch. do any of you have any experience with this? I would be going straight into dry ice after the quench and then tempering it 400 F. I have previously left these steels to the care of professional heat, treaters while I do my own regular high carbon stuff. The problem now is that either the price and the wait time have become unacceptable or, in a couple cases, these heaters are no longer taking small batches.
 
I’m watching this one. Per Alphaknife supply oil quench is acceptable for AEB-L.
 
The difficulty with the oil quench is the envelope. I did oil quench 440C and 154CM when I first started. I soon went to aluminum quench plates. Do you hold the package by the tang and cut the envelope away and then quench? Or dump the whole thing in the oil?
It can be a PITA trying to get those knives out of the bag, especially if it has stuck. Something like D2 or A2 you may be able to find coatings that tolerate the aus temp and that solves the bag problem. AEB-L and 3V need the bag for the most part. There's a guy on BF experimenting with coating AEB-L.
As far as your oils go, air hardening steels only need a "slow" oil. AAA is preferable over 50. BTW, 50 never needs to be heated unless it's cold. It's designed for room temp use, even for 1095 or W2.
A suggestion: if you own a hardness tester or have access, include an extra tab in the furnace run, wrapped separate. Take it and set it on the floor and let it cool. Then take it through the rest of your process with the blade. See how the hardness compares after dry ice.
 
Chris Railey said:
I am wondering why one would use oil instead of an air or plate quench for these steels? Just curious, not judging.
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Because the old HT instructions from the companies said "air or oil quench," for the most part, I would suspect. Followed by adhering to the worn concept that the faster the quench the better regardless the steel.
Oil quenching wrapped stainless blades became an instant thing of the past when I bought the plates. Always a mess. Plates are freakin' expensive now, though. That may send some folk in a different direction, too.
 
fitzo said:
Because the old HT instructions from the companies said "air or oil quench," for the most part, I would suspect. Followed by adhering to the worn concept that the faster the quench the better regardless the steel.
Oil quenching wrapped stainless blades became an instant thing of the past when I bought the plates. Always a mess. Plates are freakin' expensive now, though. That may send some folk in a different direction, too.
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They are expensive now. I purchased a pair on this site when I first started making knives way before I started using them. Glad I did.
 
fitzo said:
The difficulty with the oil quench is the envelope. I did oil quench 440C and 154CM when I first started. I soon went to aluminum quench plates. Do you hold the package by the tang and cut the envelope away and then quench? Or dump the whole thing in the oil?
It can be a PITA trying to get those knives out of the bag, especially if it has stuck. Something like D2 or A2 you may be able to find coatings that tolerate the aus temp and that solves the bag problem. AEB-L and 3V need the bag for the most part. There's a guy on BF experimenting with coating AEB-L.
As far as your oils go, air hardening steels only need a "slow" oil. AAA is preferable over 50. BTW, 50 never needs to be heated unless it's cold. It's designed for room temp use, even for 1095 or W2.
A suggestion: if you own a hardness tester or have access, include an extra tab in the furnace run, wrapped separate. Take it and set it on the floor and let it cool. Then take it through the rest of your process with the blade. See how the hardness compares after dry ice.
Click to expand...
I would not be putting these in an envelope. I would be using a 2000+ degree anti-scale goop. I use the high temperature, stainless foil for thermal cycling, stress, relief, and kneeling, etc. But not for he treating. I’ve used it on one occasion to wrap a mosaic Tile billet. The foil basically fell apart on the second welding heat, which was scary but convenient.
 
jmforge said:
I would not be putting these in an envelope. I would be using a 2000+ degree anti-scale goop. I use the high temperature, stainless foil for thermal cycling, stress, relief, and kneeling, etc. But not for he treating. I’ve used it on one occasion to wrap a mosaic Tile billet. The foil basically fell apart on the second welding heat, which was scary but convenient.
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I'd be interested in the name on that "2000+ degree anti-scale goop," if you're willing, please and thank you!

Edited to add: I see ATP 641 claims 2400F max. (Jantz) That might be interesting. I tried an ATP many years ago that was supposedly good to 2000F and it toasted the 440Cor ATS34 I was working with. Pitted like mad. Turns out the stuff is mostly borax, which gets REALLY acidic at those high temps. This stuff would be really interesting if it works, especially since it's paintable.

This thread on BF speaks about both ATP641 and NoScale2000 with AEBL.
 
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jmforge said:
Because I have lots of oil and no giant aluminum plate nor a compressor to blow air.
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Your logic makes sense but CPM 3V will fully harden in still air. No plates, oil, or blown air are needed. Again, no judgment, just trying to save you unnecessary steps. The good thing about working in your own shop is you can do it your way...
 
I use AEB-L almost exclusively for kitchen knives. I use Texas Knifemaking Supply for my heat treat and they do a good job but cost and turn around time are issues. So if I'm getting all this right I can heat AEB-L with no foil in my forge to some as yet undisclosed critical temp and then quench it in Canola, Does it then need to go into dry Ice and acetone mix and then oven temper at 400*. Fill i the blanks here for me guys. Thanks, Walace
 
wmhammond said:
I use AEB-L almost exclusively for kitchen knives. I use Texas Knifemaking Supply for my heat treat and they do a good job but cost and turn around time are issues. So if I'm getting all this right I can heat AEB-L with no foil in my forge to some as yet undisclosed critical temp and then quench it in Canola, Does it then need to go into dry Ice and acetone mix and then oven temper at 400*. Fill i the blanks here for me guys. Thanks, Walace
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The way I look at the world is: you can do what you want in your own shop for sure. That being said, I would not treat AEB-L in this manner, especially if you sell your knives. Most SS requires a more exacting HT process with soaks at specific temps. If you were to gain control of your forge's temps and could hold it steady at specific temps according to the protocol for AEB-L then I guess it would work. As far as foil goes, I will admit to experimenting with foil, no foil, and graphite sprays for AEB-L in my kiln. I have noticed that at times it turns out fine but there are times the blades get pitting that is not taken out during the blade making process especially on thinner stock. There is no rhyme or reason I can see as to when this happens but I can tell when it does not happen, and that is when I use foil. Please keep in mind I am a hobby guy and what I say is all from that perspective. If you really want to know about AEB-L go to Knife Steel Nerds and search for the article on AEB-L. I have read it several times.
 
Here's a link to that AEB-L paper Chris mentioned, LOTS of good info there.
knifesteelnerds.com

All About AEB-L - Knife Steel Nerds

I've gathered all of the information I have on AEB-L steel, including its history, toughness, edge retention, ease in sharpening, and other properties.
knifesteelnerds.com knifesteelnerds.com

Chris, your experience with the graphite sprays are about the same as my experience. I still use the graphite spray for carbon steel, but for SS I normally use SS foil. I just feel more comfortable with the foil packets. Oh, and quench plates for sure here.

Talking with a Sanvick Engineer years ago he said as long as the 13C26/14C28N alloys got below 1100F range in 2 minutes ( was it 2?) there was no real advantage to quenching faster. He also said dry ice solution was as good as LN, but my experience is LN is a tad better - perhaps a 1Rc or so on quench?
 
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