All: I wanted to let you know about a "new" material now available from Crucible Steel. It's a particle metallurgy version of 154CM, called CPM 154CM (DUH!!)

Scott Devanna sent me some samples of both the "old" and "new" 154CM, and I heat treated it and polished it down to see how the CPM process affected the finished appearance and workability of the steel. The difference was incredible!!!!

Using a disc sander, to produce parallel, curved scratch patterns, I could easily tell the difference at 320 grit. At 600 grit, the test blocks were nearly mirror finished.

The "old", conventionally produced specimen showed carbide streaks, and what I call "carbide clouds"-areas in the steel where the grain structure and carbides were clearly visible, and, constantly changing in appearance.

The CPM 154CM was as uniform as I have ever seen-you could see extremely small particles, but, they were completely uniform, producing a pure, evenly reflective surface that was pretty much like looking at a good mirror.

Interestingly enough, I heat treated both blocks together, and, when I checked the hardness, the CPM block was 1.5 points higher! (615 versus 60).
I immediately called Scott, and he laughed and said "I didn't tell you that, but
that's exactly what should have happened"

So, they have a winner here. I have identical blades made from both alloys-my next test will be to sharpen them and run some cutting comparisons, and, check out the ease of sharpening. I'm confident that the CPM version will kick a**!!!!!

I'll post results when I have them.

So kule!!!

RJ is the make up identical?

I think I read something about a touch of vanadium too?

Steve

Steve: The composition was the same in my samples. Scott says they are considering adding some Vanadium-the composition isn't locked down yet.

I've always thought highly of CPM, and it's benefits show up in many ways. Now to compare CPM 154cm with S30V for all properties and price too !

mete: I don't think even the new CPM154 will touch S30V in terms of performance. I'm guessing it will be a bit less expensive. I see it as very useful for higher end knives where appearance (and price-Less with CPM154, due to lower labor costs) are more important than cutting ability. Also, a good choice for a factory to upgrade to from a lesser alloy, while still being able to process in the same way(fabrication methods, not HT).

Definitely a nice option that will fill a niche in the steel arsenal.

I ordered some a few weeks ago and it hasn't gotten here yet. It seems every time I have them surface grind some thing, it gets lost- but they surface grind cheap and it's easier for them to do than it is for me. Anyway, I'm hoping it will polish up as well as RWL-34. I've got a half meter of RWL here and I'll do a comparison when I get it in and let you all know.
Interesting it would come out so much higher in RC. It's supposed to be the same composition but surely the particle processing couldn't add that much hardness?

Tracy, I would have to assume that since the carbides are smaller and more evenly distributed ,when you austenitize you get more carbon into the matrix therefore strengthening [increasing the hardness] the matrix.

RJ, please give us a grinding comparison. Does it machine differently than plain 154CM?

Nice that it solves the finishing problems, but does it take longer to get a good satin finish?

You've perked my interest.

I really like working with S30V, but it's hard to finish.

Don: Either version of 154CM machines easier and finishes easier than CPMS30V. The 154 CM grades don't have any Vanadium, which is primarily what makes S30V hard to finish and grind.

I did not notice an appreciable difference between the old and new 154CM, but I don't have a lot of data for comparison, either. Bottom line, for me at least, is that with the same degree of finishing effort the CPM154CM blank looked incredible because of it's microstructure.

It's my understanding that there is 0.2% Vanadium in this first batch of CPM-154. That would make it pretty much the same as RWL-34 which has always been my favorite high finish stainless, except for the price. RWL is VERY pricey.