Oil quenching AEB-L

Bühlmann

Bühlmann

North Lake Forge
Joined
Jan 6, 2022
Messages
475
If you are oil quenching AEB-L, is a fast or medium speed oil preferred?
 
I have heat treated close to 200 AEBL and 14C28N blanks, all plate quench with good results. This is the reason I am scratching my head about oil quench.
 
Because I don't have the proper quench plates yet. I only have two face-surfaced 2x2x0.125" angle irons that I clamp together in my tempering process. I have a small piece of AEB-L that I want to make a small test knife of a design I made for my own personal use at work and whatnot before I leave for 6 weeks for my real job. I've never heat treated any stainless before, but I saw on the AKS site that oil quenching was acceptable for AEB-L. I don't have any cryo stuff or dry ice either (I know, what a scrub right???). So for this little learning experiment strictly for my own development and experience I am heat treating in my new kiln, oil quenching, then directly into my tempering plates and into my deep chest freezer (per KSN graphs) set at -10F for an hour, then into the tempering oven for two cycles at 300F. That's what I have to work with at the moment, so I hope y'all won't beat me up too bad for not doing it the way you do it because I don't have that stuff yet. I do have a set of quench plates on order, but they won't arrive until after I leave.

*The blade is in the final tempering run right now. It came out of the quench skating a 60 file and barely gripping on the 65 file, before going in the freezer. I think that's okay....maybe not just not metallurgically perfect because I oil quenched? I did a test HT of a cutoff from when I profiled the blade and it snapped clean and the grain looks nice to me. If I've made useless junk out of this piece of AEB-L I'll know by the time I return from my job, because I am not planning on being kind to it during this hitch.
 
Here’s a pic of my HT test piece (pre-freezer, pre-temper) that I snapped to look at grain:

9606A19C-5604-48A3-AE4A-5DDB6D371AB3.jpeg
 
Bühlmann said:
Here’s a pic of my HT test piece (pre-freezer, pre-temper) that I snapped to look at grain:

View attachment 2098335
Click to expand...
Kinda not in focus and a lot of programs compress images, so I can't really say what ASTM grain size that is or estimate it but if you can get a better picture (stick your fingers near the top so it doesn't focus on them) or change how you upload it, it should show pretty easily. I would recommend using Google drive and sharing the direct link.

Overall however in my opinion it looks really good from what I can tell. Good job man!
 
_Dan_ said:
Kinda not in focus and a lot of programs compress images, so I can't really say what ASTM grain size that is or estimate it but if you can get a better picture (stick your fingers near the top so it doesn't focus on them) or change how you upload it, it should show pretty easily. I would recommend using Google drive and sharing the direct link.

Overall however in my opinion it looks really good from what I can tell. Good job man!
Click to expand...

It's just a quick iPotato pic I took, so it won't get any better. It's going to be what it is, and that's what I'm going to work with for this project. Like I mentioned, this is just for me and to practice & play around with. I'm just fumbling my way through the learning curves and trying to have some fun along the way. I think it might be good to have a reference point so when I get back and can do it again with plates I'll have some frame of reference for comparison. I wonder if there will be any real-world or even tangible/noticeable differences? Fun to find out!
 
Bühlmann said:
It's just a quick iPotato pic I took, so it won't get any better. It's going to be what it is, and that's what I'm going to work with for this project. Like I mentioned, this is just for me and to practice & play around with. I'm just fumbling my way through the learning curves and trying to have some fun along the way. I think it might be good to have a reference point so when I get back and can do it again with plates I'll have some frame of reference for comparison. I wonder if there will be any real-world or even tangible/noticeable differences? Fun to find out!
Click to expand...
There will be!

It's honestly not the picture well, it is but, if you stick your fingers at the actual break point it'll take a proper photo and I'm not sure how much uploading it here compresses it or if it does so at all. But ya very good job man. I don't see it often ha.
 
_Dan_ guilted me into trying for a few better pics. This is the best I can manage, so I hope it helps to see the grain better:

C9ADB4AD-E2D2-4C1E-A16E-2B96BF343317.jpeg

35275FD8-B81B-46BE-82DE-0ED4A3A6DA13.jpeg

4C0954CA-872B-441C-B33C-062ADCCBF8CE.jpeg

Still pretty crappy when blown up like that. Not sure what else I can do.
 
Bühlmann said:
_Dan_ guilted me into trying for a few better pics. This is the best I can manage, so I hope it helps to see the grain better:

View attachment 2098400

View attachment 2098401

View attachment 2098403

Still pretty crappy when blown up like that. Not sure what else I can do.
Click to expand...
Hahahaha I said to hold it with your fingers at the break point man! Your camera will focus on it exactly then. I would also use flash. I really wish I could give you any additional information from those pics but unless you take it on the highest megapixel ratio, or if you are then uploading them to here is what is compromising the image. The two websites that I would recommend using would be

1. Google Images and then share the image link.
2. Google Drive file share link.
3. Text me it.

I can confirm that it looks good but I may be seeing something that isn't there unfortunately I just cannot say honestly an ASTM number.

Also, something does not look right with that. The gray sides are graphite (I'd explain to you) so the heat treatment did not really work. Yes, nurcor should be fine and foil is only better when you are heat treating with a furnace. I use ATP-641 which is very similar for simple steels and oil quenching, it's not the best to be honest but it blows off nicely upon quenching. You want the coat to be the thickness of what they say, for ATP it's 7 mils. I'm not sure exactly what happened. Can you explain exactly how you austenitized it?
 
_Dan_ said:
Hahahaha I said to hold it with your fingers at the break point man! Your camera will focus on it exactly then. I would also use flash. I really wish I could give you any additional information from those pics but unless you take it on the highest megapixel ratio, or if you are then uploading them to here is what is compromising the image. The two websites that I would recommend using would be

1. Google Images and then share the image link.
2. Google Drive file share link.
3. Text me it.

I can confirm that it looks good but I may be seeing something that isn't there unfortunately I just cannot say honestly an ASTM number.

Also, something does not look right with that. The gray sides are graphite (I'd explain to you) so the heat treatment did not really work. Yes, nurcor should be fine and foil is only better when you are heat treating with a furnace. I use ATP-641 which is very similar for simple steels and oil quenching, it's not the best to be honest but it blows off nicely upon quenching. You want the coat to be the thickness of what they say, for ATP it's 7 mils. I'm not sure exactly what happened. Can you explain exactly how you austenitized it?
Click to expand...
I think the dark bands on the test piece are decarb (?) where I didn't apply the NuClayer 2000 to the edges of the scrap piece, only the flats. That is interesting. The blade got the full application of anti-scale.

Preheat for 5min @ 1560F
Ramp up to 1950F
Soak for 15min @ 1950F
Quench in AAA (a medium-fast oil I know, but slower than P50 and those are the two oils I have)
Place into clamped tempering plates described above
Into -10F freezer for 60min
Tempered 2x @300F


After everything is cleaned up, it skates a 60 Tsubosan file like glass, and I can get a 65 to feel sticky but I have to apply more pressure than I normally do in my technique. I know those files are less than perfect, but I tend to get values that are good approximations of the graphical data in KSN, and when I do not I can usually trace the reason why to some deviation in process.
 
Last edited:
Bühlmann said:
I think the dark bands on the test piece are decarb (?) where I didn't apply the NuClayer 2000 to the edges of the scrap piece, only the flats. That is interesting. The blade got the full application of anti-scale.

Preheat for 5min @ 1560F
Ramp up to 1950F
Soak for 15min @ 1950F
Quench in AAA (a medium-fast oil I know, but slower than P50 and those are the two oils I have)
Place into clamped tempering plates described above
Into -10F freezer for 60min
Tempered 2x @300F


After everything is cleaned up, it skates a 60 Tsubosan file like glass, and I can get a 65 to feel sticky but I have to apply more pressure than I normally do in my technique. I know those files are less than perfect, but I tend to get values that are good approximations of the graphical data in KSN, and when I do not I can usually trace the reason why to some deviation in process.
Click to expand...
It’s better to not preheat and ramp. Just set the temp and place blade in furnace at temperature.

Hoss
 
DevinT said:
It’s better to not preheat and ramp. Just set the temp and place blade in furnace at temperature.

Hoss
Click to expand...
Okay. I'll do that next time. I remember reading to do it somewhere, but don't remember where. Lots of older AEB-L information out there, and I'll bet some of it is outdated practice. Does preheating put too much carbon into solution?
 
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