heresy with CPM154 heat treating

rabunsmith

New Member
Usually, I just forge ordinary steel, and play with jewelry stuff. I had bought a flat of CPM154 at the Blade Show, just having heard this is the ultimate stainless knife steel. I made four good looking fixed blades. However, I have no access to a temperature controlled furnace. So, I did the ignorant and heretic approach to heat treating. Used the rose bud torch and heated the blade to light orange and plunged it in old vegetable oil. No cryo heat treat, just overnight in a 0 degree F freezer. I had forged it to shape and ground and polished it. Now I plan on keeping it for an hour at 400 deg. F. for what passes as tempering.
Will this get me into knife purgatory? Really, I know there will be lacking austenite, but can anyone predict what flaws the knife will likely have?
 
With the heat treat you described, I would anticipate that the blade(s) will be either extremely hard and brittle, or they will be too soft. More then likely it will be a combination of both. Every stainless has what's called a "target hardness"... stray from it just a couple of Rc points either way, and things get strange. I use CPM154 in some folders, and even though I own two heat treat ovens, it took me some time to figure it out, started from the recommended time/temps as a baseline. In order for me to get what I consider decent performance from it, I had to change my way of thinking/working. I upped the recommended soak time, used aluminum quench plates, and had to adjust the recommended tempering temps and number of cycles. What really threw a wrench into things for me was that when cpm154 achieves it's "target hardness", I had to change grinding geometry on the blades before it would cut to my liking and/or hold an edge. Most of my blade are forged carbon or alloy steels, and I'm used to tailoring the heat treat to fit the blade/edge geometry.....with CPM154, you have to heat treat to the "target hardness", and THEN figure out the geometry where it's heat treat works best.....kinda backwards to my routine.
 
Thanks, Ed, for your feedback. Meanwhile I used a left-over piece and ground an edge on it. Tested it first on oak by hitting the piece with a mallet. Everything is fine. Then I did the same thing to a 3/8 wide extrusion of 6063 aluminum - three times. The first two showed a bit of nicking, and the last hit broke the fine edge. I also had to straighten out one of the knife blades. The bending worked fine. I did the file test and it bit slightly, so the hardness must be just below 60 HRc. Also, when dropping the blade it makes a nice ringing sound of a hard tool. So, either the CPM154 is more forgiving in its heat treatment or I am just lucky.
 
I'm glad it seems to be working out for you! In the end, all that matters is that YOU are satisfied with the results. All too often we get caught up in the textbook "right way" or "wrong way" when it comes to heat treating. In my experience, many of those who want to argue about what to do, or not to do when it comes to heat treating are either "arm chair" experts, so wrapped up in "what the book says", they can't see anything else.

Don't get me wrong....heat treating books and/or data sheets are a good STARTING point....but they are not the definitive final word.
 
Back
Top