Stacking AEB-L During Heat Treat

Randy Lucius

Randy Lucius

Well-Known Member
Need to heat treat six steak knives of .100 thickness AEB-L. Don't really want to run six heat treat cycles. Could these be stacked 2x2 or 3x3? Would I need to increase the soak time? Thanks!!
 
Anything I could say would be a guess, which I am happy to do for you but I guess we will wait and see if a smart person replies first.
 
I am actually still pondering this one even though I decided to wait for smart people. Do you do the pre-quench at 1725 degrees? I am guessing you are plate quenching too? How many sets of plates do you have?
 
I don’t stack them. Four blades is the most i like to do at one time. I can pre-quench and final plate quench that many without feeling like i need to rush. I’ve done six at once but I feel like I’m rushing and pushing the soak times too short / long to keep them in the window.

I’ve also tried putting two small blades in one foil pack to cut down on handling time but inevitably they get crossed up / overlap in the packet and i have to fight them to get them un-overlapped to plate quench them.
 
I use
Chris Railey said:
I am actually still pondering this one even though I decided to wait for smart people. Do you do the pre-quench at 1725 degrees? I am guessing you are plate quenching too? How many sets of plates do you have?
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I use NJ Steel Baron's heat treat recipe since that's where I buy the steel. 15 minute soak at 1500 and 15 minutes at 1950. I only have one set of plates.
 
I would not think stacking them would require any additional soaking time. I would not add time for a .200 or .300 thick blade (that me be incorrect) so stacked blades should not be different. My quench plates getting too hot to be effective would be a concern across multiple quenches. The most I have tried is two sequential quenches and the plates were noticeably hotter then. If it were not for the pre-quench it would be a non issue because once you are at 1950 you could leave it there for as long as it takes to soak a couple of batches.
 
I'm the same with NJ Steel's procedure, and cryo with dry ice. I have one set of plates and use a shop vac on the "blow" port for forced air. I use nuclayer anti-scale instead of foil now. I still do them one at a time for the most part though, maybe two if they're not big and I think the second won't be sitting in too long while I'm cooling the first. It's a pain like you said when you have several to do and turns into an all day ordeal.

Someone smarter has probably figured out a better way though. I mean if you could soak them all at 1500 then take them out and stagger them in at 1950-1975 it would be easier but I'm not sure how that would affect it since they say to soak at 1500 and ramp as fast as possible to 1950. I've done some test blades like that and didn't notice a difference between them but there's always those things you don't see..
 
I definitely do not fall in the “smarter people” category, but this works for me.
I will generally do 4-6 at a time all in one foil pack, then it’s one shot out to the plates and quench. I have had issues with them crossing and so forth, to remedy that I fold up my foil flat on the table and insert them one at a time keeping the pack tight. I’ll throw in some small wood chips or a couple small pieces of paper to help evacuate the oxygen. Then I fold the top over twice and tap it closed with a hammer. If you keep that pack nice and tight, it doesn’t give me many problems. I use the 1550 for 5 and then 1975, I will generally give them 2-3 minutes there and then plate quench.
 
i have done two blades together, but i take them out of the kiln individually and oil then plate quench. i have a long narrow kiln, so opening a door quickly doesnt affect the far end much. so i take the next blade out whilst standing on the plate with first, oilquench the second take first out and freezer it. then all go into liquid nitrogen, seems to work, for small easy to handle blades, wont do it for larger ones... and i limit the number of blades so soak times are closer to each other than 5min i would even use 10f lower and increase soak times... in my oven i dont put blades side by side, because the elements are then much nearer percentage wise from one side, and shielded from the other side. sure it wouldn't make a difference in many other kilns
 
Kev said:
I definitely do not fall in the “smarter people” category, but this works for me.
I will generally do 4-6 at a time all in one foil pack, then it’s one shot out to the plates and quench. I have had issues with them crossing and so forth, to remedy that I fold up my foil flat on the table and insert them one at a time keeping the pack tight. I’ll throw in some small wood chips or a couple small pieces of paper to help evacuate the oxygen. Then I fold the top over twice and tap it closed with a hammer. If you keep that pack nice and tight, it doesn’t give me many problems. I use the 1550 for 5 and then 1975, I will generally give them 2-3 minutes there and then plate quench.
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If I am reading this correctly you place one blade then roll it once and add another and roll once more and so on until the end? So each blade has foil between them?
 
Ok, so a newby question about heat treating. I am not trying to take away from Randy's original question but this is one I'm struggling with. NJSB says that as soon as the blade is at black heat and magnetic, it can go back in for the next process. Does the kiln need to cool to a certain temp, or is it ok to put the knife back in the kiln and it will reach temp by the end of the soak cycle? I have been letting the kiln cool down to between 800 and 900 degrees before I put it back in. My logic, or lack there of, for that is the blade needs time to get up to the temp of the kiln.
 
I go straight back into the kiln for the second step. Whether it is correct by academic standards or not, I am not sure but that is the way I was taught by a maker I trust. The blade will reach temp by the time you reach 19xx degrees.
 
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Chris Railey said:
I go straight back into the forge for the second step. Whether it is correct by academic standards or not, I am not sure but that is the way I was taught by a maker I trust. The blade will reach temp by the time you reach 19xx degrees.
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Makes sense. Thanks Chris
 
I have only gang-Heat treated A-2. I have done as many as 20 blades at a time. I put a tab near the tip of the blade with a hole in it. I space each knife with flat washers.(I space them for easier cooling) And bolts through the two pin holes and the tab at the end of the blade. They come out straight as an arrow.

I wrap the entire group in a stainless pouch with a good sized piece of paper towel. I make the pouch longer so it's easier to cut open. I lay the blade-bunch in the bottom of and old shopping cart that has a box fan blowing up on them. They are consistent hardness.

I have not tried this with AEB-L...but plan on it. The only thing I may change is to make a "spine" of A-2 with matching holes to help keep the AEB-L straight when it goes rubbery in the furnace...

Hope this helps...
 
Chris Railey said:
If I am reading this correctly you place one blade then roll it once and add another and roll once more and so on until the end? So each blade has foil between them?
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No. I just make one big bag and put them all in. That way I’m only quenching one layer in my plates.
 
Kev said:
Right.
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They have a fixture that will stand the blades up right. It's expensive for what it is. I made one out of a Lightweight Refractory Brick. It works great!! Cut brick in half length wise then in half width wise. Then got a 3/8" spade bit and the cheap Harbor Freight file set to shape it. I can build 4 of these for the price of 1 Fire Brick (About $6)!!
 

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