CPM 154 heat treat recipes?

Danbo

Danbo

Joined
Nov 28, 1999
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Gotta do the heat treat on a couple of small CPM 154 blades. No time to send them off. I have the high temp foil and just need to know the proper procedures. I realize 6 different makers may have 6 different heat treat recipes, so I'm asking for some examples, please.
 
USAKnifemaker and Alpha both have HT info and/or data sheets on this steel. 1450, equalize, 1950 for 30 min, plate quench, dry ice cryo and 450 degree temper is what I have been using for this steel. I don't have a tester
but this is supposed to yield 59-60 hardness.
 
Justin gave good info.

Here's a PDF of an old Crucible data sheet.

Use stainless foil and plate quench if possible. If you're not able to do cryo after the quench, I would lower the austenitizing temperature to 1900-1925F to reduce retained austenite.

400-450F temper will give you right around 59 RC according to my tester, maybe a point higher if you use the 1950-1975F range and do cryo.

--nathan
 
I do
1200 soak 15 min,1600 soak 15 min, 1950 hold 40 min,plate quench,LN cryo overnite then 2 tempers @425 gives me a steady 60-60.5 Rc.
Stan
 
Danbo: You can skip the pre-heats and go into the furnace @ 1950. 25 minute soak is plenty. Ln2, then 2 tempers @ 450.

RJ
 
I use:
1400 for 20 min
ramp to 1925 for 30 min
plate quench to room temp
Dry ice sub-zero quench overnight
temper at 425 for 2 hours - twice


As mete has pointed out to me, cryo is at 300-400 below zero and dry ice is 100 below. Dry ice works fine for CPM-154 in my experience. It actually does not need a lengthy time at -100F to finish the transformation, but I just leave it there overnight.
 
Danbo, hope you don't mind a little thread drift here:o

I'll be doing my own heat treat soon since I've got an evenheat coming in a bit and I have some of the same questions because I use a lot of CPM-154 also. Already subscribed to this thread to keep track of the methods used.

One question about dry ice. How is it best stored? Also, how long does it last? Do I have to go out and find more dry ice every time I heat treat a blade or does the stuff last for a while in the freezer? I've never had much reason to use it except for making "smoke" at a halloween party years ago. Thanks!
 
The dry ice is a per-batch item, unless you have a special freezer it won't keep very long. I have my wife pick up a block on the way home from work when I am doing a HT run, I like to have the oven warming up already when the dry ice comes out of the store. A 4lb block has a 12-16 hr life span from this point on, if kept in a well-insulated cooler.
 
For all practical purposes, you'll have to get new ice every time you heat treat. Putting it in the freezer won't really lengthen your time much; it tends to go away pretty quickly. Even in a freezer, your temperature differential is about 100F+ between the freezer and the dry ice. When used to cryo, it's gone in a day or less depending on how it's used. LN can be stretched out a bit more with a good dewar. My dewar will hold LN for about 6-8 weeks when filled up.

My suggestion is to work in batches and then go grab all the dry ice you need to cryo the batch. That will stretch your time out a bit between ice runs.

--nathan
 
Thanks for the responses guys, but with respect to my buddy Danbo, I'm going to ask the rest of my questions in a new thread.

Thanks for renting me out a little space Danbo!! I'm outta here:D
 
hey guys, i got a question that i can seem to find on google ANYWHERE i look, i just started getting into making knives and was wonder how you might go about cryo treating blades, a step by step would be awesome in both LN and using dry ice, cant seem to find info but everyone always mentions doing it. also, once i get to the point where i need it, where are some good suggestions on buying LN? thanks
 
Basically, after your heat and quench, you go straight into your cryo or cold treatment. Immerse in LN or a dry ice slurry. I usually just do it towards the end of a day and leave the blades in cryo overnight. [[Some people do a snap temper first (below 300F I believe for about 30 minutes) prior to putting the blade into cryo. This supposedly can reduce risks of cracking a blade, but I've never had an issue or a crack with stainless going in right after quench once the blade reaches room temperature.]] After the time in cryo, just pull the blades out and let them warm to room temperature. Go directly into your temper once they've reached room temperature.

LN needs to be stored in a special container called a dewar. DO NOT use any container that seals. LN WILL gas off no mater what it's in short of high strength specialized transport tanks. If you put it in something that seals, it will explode. LN can be bought at any industrial gas supply like AirGas. Dry ice can be bought in most supermarkets or in dry ice suppliers and contained in styrofoam coolers.

--nathan
 
Just now getting my oven up and running. Looking at heat treating CPM 154 as well. A question on cryo, or dry ice. Would it hurt to harden then do a temper cycle then a day or two later cryo, then temper again? Closest dry ice or nitrogen is 45 minuets one way. Also is plate quench the way to go vs. a fan blowing across the blades and with either method do you need to remove from the foil? Now if I can just figure out how to work the Sentry 2 controller!

Thanks,

Will
 
Will, waiting any significant length of time and/or tempering higher than 300F or for a long period will stabilize the retained austenite and negate the potential benefits of converting that RA into martensite. My suggestion is to get all your ducks in a row and then go to work.

As for quenching, in my mind, the plate quench will probably be faster than a fan blowing on the blade. I would think it will also results in more even cooling. The plates act as a giant heat sink and pull the heat out of the blade. Either way will result in a hard blade, and either way, I would leave the blade in the foil to quench.

--nathan
 
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