Aebl toughness?

funkyjedi

Well-Known Member
Ht'd some aebl for the first time. I ground before ht, and thought it wasn't holding an edge as well add i hoped it would. I stabbed some mdf and then pressed the edge on a copper rod. Kablewie! How tough should this stuff be?

I followed a ht recipe from this forum exactly. Scratching my head.....
 

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Wow! I've just recently switched to AEBL from my old favorite 14C28N. I haven't done much testing yet though, so I'm curious about this one too. Post up your ht recipe, maybe that will help to analyze.
 
First of all, what thickness is the blade? What type of grind? How thick is the metal at the back of those chips?
 
It could be one of several pieces of the heat treat process. It could also be the edge is a bit too thin for that heat treat/steel combination. Generally, I find stainless to be "chippier" (what ever that is) than high carbon steels.

What hardness is your blade?
How are you heating and quenching?

Start tuning your heat treat by adding 25F degrees to the temper and test again. If you have to increase by 50F, you start looking at other parts of your process.

If you don't have a way to test hardness, you have to do testing like this to failure to dial in your process.
 
i would be surprised at that performance if the edge was say more than 0.01" thick... about 0.1-0.2" behind the edge... it is definitely not brittle as it shows deformation before it broke, I would rather vote that there is some RA left over or that it got overheated in the grind, provided it is thick enough for what you did, the poor edge holding rather points to overheating the edge... it is more susceptible to that than some of the other high carbide stainless like elmax and m390... but difficult to tease out, hardness testing might rule out or confirm ra
 
Unfortunately I do not have a way to check the hardness. A file skates cleanly over the edge. The knife was hollow ground on a 12" wheel.

The edge at the chip is .007" and the back of the chip is .013"

It seems hard, I was just surprised that it chipped out. I finish ground it after ht with dips in water if not every pass, every other pass. I made two knives, and the one that didn't chip sharpened out well, but needed touch ups sooner than I thought it might. Anyway, the ht went as follows:

"1,940°F Austenitize: Ramp to 1,940°F and hold at temperature for 15 minutes. Oil or plate or air quench as quickly as possible.

1,975°F Austenitize: Ramp to 1,975°F and hold at temperature for 5 minutes. Oil or plate or air quench as quickly as possible.

Cryogenic Treating: To get the most from AEB-L you must cryo. Cool to -95 °F. No soak is required."

I plate quenched with .75" aluminum plate and forced air.

The only different thing I did was to temper once at 400 for about 1.5 hours.

My kiln will get to 1975 in about 10 minutes, so the ramp up seemed appropriate.
 
That sounds good, i would soak a bit longer than that... and i would put in a hot oven, but i cant imagine it makes a difference in your case
 
I think try put it in at temp - whichever works for you - and leave it in for 20min from when oven is back at temp i think the knife will be at temp for about 8 min then... but i think invest in some samples that you send for hardness testing. Look what temp and time gives you the best hardness for your methods
 
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