Heat treating my first large batch of AEB-L - this make sense?

S

StuNY

Joined
Feb 16, 2014
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So far I have been heat treating AEB-L in my oven two knives at a time. I have a good process down and am getting good results. Now that I have a couple patterns I like (chef knives) I have started on a number of multiples for gifts. I am going to treat 6 or 8 this weekend but think I have to modify my process due to the quenching time required for all of these- I probably don't want them in the oven at the same time for an extended period. So here is my thinking.

Current process:
I put two knives (foil wrapped) in the oven and ramp to 1560, holding there for 5 min
Then ramp to 1995 and soak for 5 min
Take out of the oven, plate quench (Aluminum)
Dry ice and alcohol bath
Two tempers at 375 for two hours

New Plan:
Do the first two knives per above
Then let the oven drop from 1995 to 1560 while I am quenching/tempering,
Place the next 2 cold knives into the oven for 5 min then ramp to 1995 and soak for 5 min.

I am thinking this will give me time to do the quench/dry ice bath for each pair without leaving the rest cooking at 1995 for too long, and give me a chance to cool down my quench plates.

Am I overthinking this? Should I just put all of them in at once and not worry about some of them sitting at 1995 for 10-12 minutes?

Appreciate any advice!
 
I think your 'staging' plan makes good sense. Often the timing is way to obvious to us when we think it all the way through--which it sounds like you did. I would start with that plan, but have a plan B if your first second batch gets to heating to long so you can turn thing on or off to keep your timing in check.

Good luck to you!!
 
how about oil quench then leave in dry ice bath until all are done? or oil quench to black, then plate till you can touch, then dry ice bath until all are done. have you tried skipping the pre-heat?
scott
 
Thanks guys!
Hadn't thought about oil quench- everything I have read about stainless has been to plate quench. Also not sure about skipping the preheat- anybody try it? My processes are all based on recommendations here, and I don't understand the science well enough to experiment much. I think I will make up some test coupons and try a couple scenarios- full batch at once with delayed removal of some, and then a trial where I just leave the oven at 1995 and place cold steel in directly. I always think of a heat treat run timed around when I can get a batch of dry ice, but never occurred to me for some simple tests I can just skip that part. Thanks for the inspiration to do some trial and error!
Stuart
 
StuNY said:
Was looking at the Sandvik site and it seems the preheat isn't necessary? I am going to try some coupons that I put into the oven at full temp and see how they compare to my regular routine.

http://smt.sandvik.com/en/products/...-13c26-piece-hardening-deep-freezing-70c-95f/
Click to expand...

if you read a little further at the sandvik site, no mention is made of pre-heat and they recommend oil quench http://smt.sandvik.com/en/products/...teel/hardening-guide/the-hardening-procedure/
scott
 
Yeah, just not sure I have the ability to cut it out of the foil and quench before the recommended 2 minutes. Usually takes me a while when they are cold- probably longer at high temp. Also worried about warping in oil vs the plate quench.


Sent from my iPhone using Tapatalk
 
The pre-soak idea for AEB-L came from DevinT, who is (from my understanding) the premier and foremost authority on HT'ing AEB-L. He covers the process in this thread: http://goo.gl/bqD3PK where he suggests - "IF" you only have one oven) dropping the pre-soak but staying with the 1725ºF pre-quench, then direct to 1975ºF quench......

Sandvik mentions oil quench, but the main thing from Sandvik is to get temperature below 1100ºF (1200?) in less than 2 minutes. Plate quench works good for this, and goes a LONG way to preventing wrap
 
Just put them all in the over at 1560F and ramp to 19995. Soak the desired time. Pull them one or two ( depending on your plate size) at a time and plate quench. After 120 seconds in the plate, pull out and set aside. Repeat until all are out of the oven. Once all are done and cooled to room temp, remove from the packets and put in the dry ice bath. Leave in the bath for 10-30 minutes and then let warm to room temp. Temper twice.

The additional time won't hurt anything.
 
Thanks Stacy! The additional time was my worry- great to know that is not a problem as it sure simplifies things for me!
 
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