AEB—L conundrum

[Kev]

I’ve recently heat treated some AEB-L, using a tried am true method I’ve used dozens if not hundreds of times. I was treating a fillet knife that I had ground fairly thin. When I was finished with the plate quench the blade was still dead soft. Could the relative thickness be the reason?

 

[John Wilson]

I don’t think so. I use AEBL from .070 on up to .165 and I have never had any that didn’t harden.

I think you got sent some bad supplies.

 

[Gene Kimmi]

How soon was this after taking it out of the plates? It takes a little time before they completely harden.. When I take AEB-L out of the plates, it is still fairly easy to bend. I have to be careful taking them out of the foil. This is with .070" or thinner blades once they are cool enough to handle. After I get them out of the foil. I lay them on a flat plate and do any straightening that is needed.

 

[KenH]

Gene's got the right idea. When AEB-L is first taken from quench plates it's like a wet noodle.... well, almost anyway. Got to get real cool before it starts to harden up to any extend. I once checked Rc from quench plates and didn't wait long enough and the blade only tested around 45 Rc. Let it cool an hour and it was back up in the low 60s as it should have been.

 

[bladegrinder]

AEB-L is a strange animal, like Ken said I've rockwell tested it and found it getting harder from around 150 degrees to room temp, then dry ice really makes it hard.
the thicker AEB-L is great to work with, I grind my bevels pre heat treat but the thin kitchen, filet blades are almost a nightmare. you need to have your ducks in a row to heat treat the thin stuff. I even use plates when I put them in the dry ice.

It warps when you clean it, cut it, profile it, drill it, I think if you left it in a dark room overnight it would warp.