Heat treated AEB-L without turcoat what to do.

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bronyblacksmith

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Nov 6, 2012
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This morning I was heat treating some knives and for got to put turco on one of them before I did the heat treat. The knife in question is a .110 thick AEB-L kitchen knife that I have not started grinding on. so my questions are would this have in any way damaged the final product and would it just be easier to restart?
 
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I kindly say it doesn't "need" to be. You would just grind the decarb off. I have had good experience without the foil and know some notable bladesmiths who do the same.
 
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Here is how I heat treat it and it is wrapped in foil. If you put a stainless blade in an open forge or oven for 15 minutes at 1950F you won't have anything worth sharpening. Stainless steels need to be enclosed in a sealed stainless foil packet before HT in a controlled programmable oven.

1. Heat to 1560 and equalize.
2. Heat to 1950 and soak for 10 min..
3. Plate quench.
4. Sub-zero/cryo.
5. Double temper 2 hours each time.
 
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Chuck Gedraitis Knives said:
Here is how I heat treat it and it is wrapped in foil.

1. Heat to 1560 and equalize.
2. Heat to 1975 and soak for 10 min..
3. Plate quench.
4. Sub-zero/cryo.
5. Double temper 2 hours each time.
Click to expand...

that is basically what I did without the foil. mt question is should I scrap it and start over because its ruined or finish it if the only problem is thick scale.
 
I always use foil for stainless.

I wasn't aware of a Turcoat ( Turco?) product for stainless HT at 1900-2000F.

If the steel was in the oven unprotected for half an hour at 1900+F, I would probably just scrap it. If you want to grind the bevels abnd test the edge, it won't hurt, but I would think there will be issues.
 
bronyblacksmith said:
that is basically what I did without the foil. mt question is should I scrap it and start over because its ruined or finish it if the only problem is thick scale.
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In my experience it is fine just grind the crud off. I'm not going to name drop but people HT AEB-L without foil. Just finish it out and test it, see for yourself. Good luck.

One thing that might be different is I only drill the holes and barely start the bevels. Most all my grinding on thin AEB-L is done after heat treat. And I harden in the 1960 range for shorter soak time. I Rockwell test my blades and every once in awhile have them tested by someone else. I cut hemp rope, hammer through pennies, even chop wood with chef's knives at 61 hardness. I will stand by my results.
 
Stacy E. Apelt - Bladesmith said:
I always use foil for stainless.

I wasn't aware of a Turcoat ( Turco?) product for stainless HT at 1900-2000F.

If the steel was in the oven unprotected for half an hour at 1900+F, I would probably just scrap it. If you want to grind the bevels abnd test the edge, it won't hurt, but I would think there will be issues.
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What is the issue? Does the carbon get drawn out of the steel to form the scale, leaving the underlying steel with too little carbon?



And I looked for a temp range for Turco without success, the data sheet does say it is for heat treating stainless:
http://krayden.com/technical-data-sheet/henk_turco_pretreat_tds/
 
Pattern welded steel spends, sometimes dozens of hours at welding heat and it is still fine. The hardening times and temps you used will have no effect on the final product since you have not ground bevels in. If you had already ground the edge to .015 or so, you would have to grind the profile down until you got to hardened steel but the whole thing would still not be garbage, your blade is fine.
 
JMJones said:
Pattern welded steel spends, sometimes dozens of hours at welding heat and it is still fine.
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You mean the kind of steel thats covered in flux at those temperatures and then normalized before heat treat?

JMJones said:
The hardening times and temps you used will have no effect on the final product since you have not ground bevels in.
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How is that even remotely true? You're saying he could have heat treated the blade at 2400 degrees and soaked for 12 hours and it would be fine as long as he ground the bevels in after?
 
FTO_dude said:
You mean the kind of steel thats covered in flux at those temperatures and then normalized before heat treat?



How is that even remotely true? You're saying he could have heat treated the blade at 2400 degrees and soaked for 12 hours and it would be fine as long as he ground the bevels in after?
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My pattern welded steel is never "covered in flux" and the flux is only used during the welding - which is only slightly hotter than forging temps.

I'm not sure what point either of you are making. Carbon forging steel is not AEB-L, and the scale's affect on the underlying steel shouldn't be something to debate. Either it decarbs it, or it doesn't. And 2400 for 12 isn't the time and temp the OP used.
 
Most forge atmospheres are reducing, where s kiln doesn't have that luxury, usually.

I'd be concerned with such thin stock thickness at these temps.

Shaw Blades, are you doing this work in a forge or a kiln? Just asking - no reason to argue, just want to know!
 
Matthew Gregory said:
Most forge atmospheres are reducing, where s kiln doesn't have that luxury, usually.

I'd be concerned with such thin stock thickness at these temps.

Shaw Blades, are you doing this work in a forge or a kiln? Just asking - no reason to argue, just want to know!
Click to expand...

Kiln .
 
FTO_dude said:
You mean the kind of steel thats covered in flux at those temperatures and then normalized before heat treat?



How is that even remotely true? You're saying he could have heat treated the blade at 2400 degrees and soaked for 12 hours and it would be fine as long as he ground the bevels in after?
Click to expand...


The reason for foil is to prevent decarb. Stainless blades are often ground very close to final dimensions before heat treat so a few thousanths of decarb could negatively impact performance. Decarb really only goes a few thousandths deep into the blade unless long times at very high temps are used. In my reference to pattern weld, the extreme end of time and temp, was to illustrate that even that extreme doesn't destroy the carbon content of the steel. He will have looooong ground through the decarb before his final dimensions are met, assuming he shortens the profile a least a handful of thousandths to grind through the decarb not just from the sides but from the bottom face of the steel too.
 
JMJones said:
The reason for foil is to prevent decarb. Stainless blades are often ground very close to final dimensions before heat treat so a few thousanths of decarb could negatively impact performance. Decarb really only goes a few thousandths deep into the blade unless long times at very high temps are used. In my reference to pattern weld, the extreme end of time and temp, was to illustrate that even that extreme doesn't destroy the carbon content of the steel. He will have looooong ground through the decarb before his final dimensions are met, assuming he shortens the profile a least a handful of thousandths to grind through the decarb not just from the sides but from the bottom face of the steel too.
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And you don't think carbon migration is a factor?
 
The temperature inside the foil envelope is going to be the same as if there wasn't any there.
Frank
 
RX-79G said:
And you don't think carbon migration is a factor?
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Nope. Carbon migration is sloooooow. If I remember correctly, it is only like 5 thousanths per hour at these temps. That is exactly why thin cross sections must be foil wrapped and thick ones it makes no difference because it will all be ground off.
 
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