ABE-l Heat treating help

J

Jwgriesser

Joined
Sep 20, 2015
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I used this formula:
Alpha Knife:
Heat Treating Information:
Preheat: Heat to 1560° and equalize.
1920°F Austenitize: Ramp to 1940°F and hold at temperature for 15 minutes. Oil or plate or air quench as quickly as possible.
1975°F Austenitize: Ramp to 1995°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.
Temper: Temper immediately after hardeneing or cryo. Temper at least 2 times for two hours each time.


I read that cryogenic only increases the hardness by 1 or 2 points. I didn;'t do this. I did everthing else.

Here is my problem: I used A Goodson Detroit Harness Tester Model HT-45RC and can't get a reading. I am not sure if it is my device or my heat treat.


Is there a low tech way to check for hardness?

Any ideas would help!

Thanks Jay
 
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We refer to temperatures about -100 F as 'sub-zero'
We refer to temperatures about -300 F as cryo also LN [liquid nitrogen temps]. Cryo also needs time ,I usually say 4 hours The formation of eta carbide happens when tempering .

Where's "table bellow " ?
 
Devin Thomas aka Hoss recently posted one of his recipes on here. He is one of the acknowledged masters when it comes to that particular steel, so it would be worth looking up. IIRC, he does "prehardening" quench at 1750F before gong to the final handing/
 
I find that you must do a sub zero cycle with AEBL to make it harden correctly. I have not checked out Devin's ht recipe though, I'd certainly look into that.

I go straight to subero after hardening... hand cool thoroughly, water dunk then dry and sub zero.

Once AEBL has been ht'd to potential it is really hard to beat, I'm going to use it almost exclusively for my knives this year.
 
When I started out using AEB-L I had a recipe for HT without a sub zero quench. It did involve using the freezer for an hour as I read somewhere the metallurgist from BU had suggested it as a minimum. The knives were 60Rc and performed well. I will post it if I can dig it up.
 
Jwgriesser said:
Here is my problem: I used A Goodson Detroit Harness Tester Model HT-45RC and can't get a reading. I am not sure if it is my device or my heat treat.


Is there a low tech way to check for hardness?

Any ideas would help!

Thanks Jay
Click to expand...

What do you mean that you can't get a reading? Even if it didn't fully harden, you should get a reading, and yes there is a poor-mans way of testing HT, see if a file will skate or dig in.
 
AEB-L warps like a son of a bitch. So keep that in mind. The steel is still pretty plastic out of the foil, so that's good. Prepare to straighten.

Here's a recipe I used for this steel that helped me alot.

Preheat kiln for an hour at 1950 deg
Knives in -15 min soak
Plate quench
Dry ice and acetone/alcohol mix for 30 mins
Temper 340deg - 2hrs
Water quench until cool
Sub zero again 30 mins
Temper 340deg 2 hrs
Water quench

RC -62
 
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Josh Mason said:
AEB-L warps like a son of a bitch. So keep that in mind. The steel is still pretty plastic out of the foil, so that's good. Prepare to straighten.

Here's a recipe I used for this steel that helped me alot.

Preheat kiln for an hour at 1950 deg
Knives in -15 min soak
Plate quench
Dry ice and acetone/alcohol mix for 30 mins
Temper 340deg - 2hrs
Water quench until cool
Sub zero again 30 mins
Temper 340deg 2 hrs
Water quench

RC -62
Click to expand...

What thickness are you working ??
 
Josh Mason said:
AEB-L warps like a son of a bitch. So keep that in mind. The steel is still pretty plastic out of the foil, so that's good. Prepare to straighten.

Here's a recipe I used for this steel that helped me alot.

Preheat kiln for an hour at 1950 deg
Knives in -15 min soak
Plate quench
Dry ice and acetone/alcohol mix for 30 mins
Temper 340deg - 2hrs
Water quench until cool
Sub zero again 30 mins
Temper 340deg 2 hrs
Water quench

RC -62
Click to expand...

Josh, a couple of extra minutes in the foil will minimize or eliminate your warpage problems. I find that leaving it in the foil until I can handle it with bare hands works best for me. I used to have the same problem when I was removing it from the foil with gloves. AEB-L almost feels like tin until it gets to almost room temp., especially thin kitchen knife stock.
 
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