Results of AEB-L coupon test...not conclusive

Patrice Lemée

Patrice Lemée

Joined
Aug 13, 2002
Messages
5,703
Sorry for starting yet another AEB-L thread. :o Seems like every second thread is about that steel theses days.

Following the advice from Hoss, I cut 5 coupons of AEB-L (0.129). Heat treated them using aluminum plates in a vise setup, like many have, and stainless foil of course. Did not do the cryo yet but figured it would still give me a good starting point.

aebl_coupons1.JPG


Prequench: soak 1725F for 20 minutes
Cooldown to room temerature
Quench: soak for 10 minutes at temp

Ground just enough to get fresh steel and got these readings along the coupon. Last reading () is in a corner, very close to the edges.

1900 – 57 - 56.2 - 58.2 - 57.2 - 57 (56.4)
1925 – 56 - 55 - 57.5 - 57.9 - 57.7 (58.4)
1950 – 57.5 - 58.3 - 58.8 - 57.5 - 57.4 (56.8)
1975 – 56.1 - 58.1 - 58.6 - 56.5 - 57.4 (55.4)
2000 – 57.5 - 57.4 - 58 - 56.9 - 57.3 (54.4)

Gives me these average removing high and low readings

1900 – 57.06
1925 – 57.06
1950 – 57.77
1975 – 57.33
2000 – 57.40

Doesn't make much sense. :confused::confused::confused: Plus shouldn't be able to get at least 60 maybe 61 even before cryo?
On a side note, my hardness tester is quite old but still fairly accurate from what I can test with my standard.

Any ideas of why this is not working? What am I doing wrong?
 
Wow. That gives you nothing to go off of, other than trying to figure out wether your hardness tester needs calibrated or if you need a faster quench. That would be a frustrating test.

One question. Did you quench after pre soak or just cool to room temp?
 
lol exactly, quite frustrating.

I quenched after 20 minutes at 1725 then let cool to room temp. (plates get it close to room temp in a hurry anyway)
 
Room temperature is not sufficient for AEB-L. It has to drop to at least -100°F/-70°C to finish the quench and fully convert. I suspect you have massive RA.

Take one coupon and re-do the HT with a dunk in a dry-ice slurry or LN as the finish. I bet the hardness jumps considerably. IIRC, Rc 57-59 is all you will get with a room temp plate quench.
 
The last few months I have done quite a bit with AEB-L and tried to read everything I could find about heat treating it. I believe Stacy is spot on, as your results would suggest.
 
Patrice, You got about the same results I got - I did manage to get 60 Rc from quench plate only, but that was next morning. Normal values are just as you have direct from quench plates (5 minutes after quench) of 56 to 58, with some 59 Rc. That is why I started the thread other day about "post quench Rc for AEB-L??". Only one response to that thread who say 62Rc direct from Quench plates. His went up to 64 Rc after dry ice treatment.

The frustrating is Sandvik steels consistently give me 61+ Rc direct from quench plates, then to either -5ºF or a -95ºF treatment. The HT info for AEB-L from AKS shows 64 Rc direct from quench plates with only 1940ºF for 15 minutes.

I've not used 13C26, but have used 12C27 and 14C28N (my favorite) and by following Sandvik's HT info I get Rc to match pretty close to Sandvik's published specs. I sure wish AEB-L worked the same way.

Ken H>
 
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Thanks a lot guys. Relieved to know that the results are normal without cryo. Found a place that actually delivers dry ice so I am well on my way to give it a try. Only need to take care of a hand/thumb sprained before I do. Hopefully it's not serious enough to keep me from the shop.

Anyway, a follow up question.

Will the cryo treatment also give me more uniform results on each piece? I was surprised of the range I get over one particular piece.
 
Try soaking at aus temp longer, some ovens are slower than others, even though the temperature recovers the blade might not be at temperature.

Do a coupon at 10 minutes, then at 15, then at 20 and see if there is a difference.

There is material being sold as aeb-l that was not made by Uddeholm. Sometimes processing can make a difference.

Hoss
 
Patrice Lemée;15600887 said:
Thanks a lot guys. Relieved to know that the results are normal without cryo. Found a place that actually delivers dry ice so I am well on my way to give it a try. Only need to take care of a hand/thumb sprained before I do. Hopefully it's not serious enough to keep me from the shop.

Anyway, a follow up question.

Will the cryo treatment also give me more uniform results on each piece? I was surprised of the range I get over one particular piece.
Click to expand...


Check the meat market at the supermarket. Some sell dry ice. I get mine from the welding supply store. Call around, you will likely find it close. :thumbup:
 
Devin if it's not too out of line can I ask were you source your AEBL from? Thanks
 
Direct from Uddeholm. Alpha knife supply has the same steel in smaller quantities.

Hoss
 
Thanks, we buy ours from Alpha as well..I was curious because I saw your comment about aeb-l from a different manufacturer. I don't know if that was it or what and I don't even remember who we bought it from(I do know it was NOT alpha) but anyway. We had a batch a year or so ago that did not react to the same heat treat that we always used the way it should have. There was a marked difference.
 
Mind if I toss in 2cents...

5 coupons ~57rc (w/i 1 rc) could indicate massive RA - as Stacy called it. But why this much RA for this steel? So I suspect, there were too much carbon in solution at this range of aust temperature. This can easily check by - take 1950F(mid point) coupon temper to 975F for 5 minutes water quench. Test hardness - if reading 52-56rc, this steel has less than 0.75%C, hence probably be aebl/13c26/14C28N. If getting higher than 57rc - you are dealing with steel has more than 0.8%C and or higher alloying fraction. Of course, this categorization is over simplied (or grossly generalized).


Patrice Lemée;15600090 said:
Sorry for starting yet another AEB-L thread. :o Seems like every second thread is about that steel theses days.

Following the advice from Hoss, I cut 5 coupons of AEB-L (0.129). Heat treated them using aluminum plates in a vise setup, like many have, and stainless foil of course. Did not do the cryo yet but figured it would still give me a good starting point.
...
Prequench: soak 1725F for 20 minutes
Cooldown to room temerature
Quench: soak for 10 minutes at temp

Ground just enough to get fresh steel and got these readings along the coupon. Last reading () is in a corner, very close to the edges.
...
Gives me these average removing high and low readings

1900 – 57.06
1925 – 57.06
1950 – 57.77
1975 – 57.33
2000 – 57.40

Doesn't make much sense. :confused::confused::confused: Plus shouldn't be able to get at least 60 maybe 61 even before cryo?
On a side note, my hardness tester is quite old but still fairly accurate from what I can test with my standard.

Any ideas of why this is not working? What am I doing wrong?
Click to expand...
 
Patrice - what are your results if you just ramp up to 1975ºF or so, then plate quench? What Rc do you get then? About the same as your 5 coupon test?

I agree with you, per the HT info for AEB-L from AKS shows 64 Rc direct from quench plates with only 1940ºF for 15 minutes. This is WITHOUT any dry ice (-95ºF) treatment. Why can Patrice nor I get those results when following their directions? It works for Sandvik steels.

Seeking to learn.

Ken H>
 
Kentucky said:
Thanks, we buy ours from Alpha as well..I was curious because I saw your comment about aeb-l from a different manufacturer. I don't know if that was it or what and I don't even remember who we bought it from(I do know it was NOT alpha) but anyway. We had a batch a year or so ago that did not react to the same heat treat that we always used the way it should have. There was a marked difference.
Click to expand...

Kentucky,
I got my last order from NJSB, maybe you ordered it through him?
 
greenjebadiah said:
Kentucky,
I got my last order from NJSB, maybe you ordered it through him?
Click to expand...

We buy a lot of steel through Aldo but I don't remember. Also have bought it from a couple other places as well as trading steel with other makers..Its hard to keep track..I do remember uping the soak and aust temp a bit to get it were it was needed though..Could have just been that batch. We buy most of our steel from Also but most of the stainless and CPM steels come from alpha because of the small ammounts you can get and price. Also they have about the best prices on G10 around to be had..
 
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Was hoping for a chemical cert for the exact melt. Did the steel come from aldo or alpha?

Hoss
 
Ken H> said:
Patrice - what are your results if you just ramp up to 1975ºF or so, then plate quench? What Rc do you get then? About the same as your 5 coupon test?
Click to expand...

I did a small knife before this with simply 1940ºF for 15 minutes and got closer to 59RC.

Ken H> said:
I agree with you, per the HT info for AEB-L from AKS shows 64 Rc direct from quench plates with only 1940ºF for 15 minutes. This is WITHOUT any dry ice (-95ºF) treatment. Why can Patrice nor I get those results when their directions? It works for Sandvik steels.
Click to expand...

Exactly!

On a side note, this AEB-L comes from Aldo.
 
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