ATS-34 Quench Plate & Cryo?

jhiggins

jhiggins

Joined
Jul 11, 2003
Messages
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Serves me right for venturing out into the world of heat-treating stainless, but I was thinking of HTing some ATS-34 blades using my aluminum quench plates and a cryo temper. Mete, Roger, Kevin, and others... would you guys care to comment on a specific recipe for this? I was thinking of tryong the following prodecure:

1. Soak at 1900F for 30 mins
2. Plate-quench.
3. Temper at 800F for 1 hour.
4. Cryo at -300 for 1 hour.

I am thinking I can get 60RC with this. Comments from you folks who have experience in this would be warmly recieved. Thanks! :)
 
I'm not one of the experts you asked for by here's my 2 cents worth. I've heat treated quite a bit of ATS34 lately. Obviously a tight, double folded foil pack, no larger than it has to be - with a piece of paper inside to burn off oxygen before the blade gets anywhere near hot. Do a 20 minute pre-soak at 1400 - then go to either 1900 or 1950 - I use 1950. Soak there for between 30 - 45 minutes (the temp is critical - not so much the time.) Remove from the oven and still in the foil pack place it on the aluminum plate - the other plate on top and add weight. You will be amazed at how clean it comes out when you don't expose the red hot steel to the atmosphere.

Flash temper when hand cool - I use 350 degrees and at least one hour - just to take the stresses off. Cryo for at least four hours - it doesn't have to be -300 - transformation occurrs and is recommended at dry ice temps ~-110. Longer and colder doesn't hurt - it just doesn't help.

From the dry ice, do two - two hour tempers, cooling to room temp between them. The high temperature ranges should be avoided. They give lower corrosion resistance and toughness. I suspect your RHC60 will come from about 500 degree tempers. If it was me, I'd do the first one at 400 - test the hardness and if needed, raise the temp for the next temper.

By the way, ALL of this - except the rockwell test - can be done still in the envelope. The only problem is steel so thin that the folds keep the plates off the steel. In that case, you would have to keep the folds outside the plate.

Rob!
 
What Rob and Mete said.
FYI,after cryo you have created untempered martensite.You must temper again after cryo.
Stacy
 
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