Steel Junkies: A new laminate S 90V clad with cpm 154 cm FYI

[The Mastiff]

That is a surprising choice in my opinion. I have heard of damascus made of 3V and ATS 34/154cm but nothing like S90V clad in CPM 154. That is going to take some thinking, and then some testing before I am convinced that it really brings an improvement to the table over regular S90V.

To the user, not knife maker I mean.

Yes, I agree and have stated the cladding steel 420J is way too easy to scratch so yes, I imagine this could be a benefit. I'm not really seeing other improvements in performance as a user though. I wouldn't expect it to be less expensive than either component steel. Performance wise S90V is very near the top of the heap already in performance for EDC folder type use.

I'm not trying to convince anyone of anything and until it's in their hands no one else should either unless it's from a different perspective other than performance until it reaches peoples hands.

Would I take it over the Super Gold/ VG2 clad already in use by another manufacturer? I'd say probably, yes. Of course that isn't exactly an apples to apples comparison though. S90V already outperforms the primary for me ( the SG1 or 2 they use) in all except possibly toughness. The CPM 154 would be closer to Super Gold performance wise but I like it better and it's only the cladding. :confused:

Naturally though I'll have to buy at least one to try out. :o

[The Deacon]

Ed, one question, since it's not totally clear to me from your posts. Is the cladding material Crucible's CPM-154 or is it 154CM made by Crucible? If the former, the jump from laminate to powdered metal damascus would seem easier, at least to my (mostly steel illiterate) mind and, given my fascination with Damasteel, that's something I'd find truly exciting.

[Dr Heelhook]

Yeah, a mirror polished blade in that material sounds pretty gosh darn sexy.

[Zenith]

I believe this should be interesting.

[KardinalSyn]

Wonder what the price factor / performance would be like on the first production runs.

[gaj999]

Wonder what the price factor / performance would be like on the first production runs.

You know, a run of Mules could answer that ...

Gordon

[phillipsted]

You know, a run of Mules could answer that ...

Gordon

Beat me to it, Gordon! A Mule would be the bee's knees.

TedP

[Pinetreebbs]

Mr. Schempp, thank you for another steel education lesson.

Polished blade and,

The S90V CPM 154 CM recommendation was for folder blades and kitchen use.

Just what I wanted to hear.

[Pinetreebbs]

You know, a run of Mules could answer that ...

Gordon

Beat me to it, Gordon! A Mule would be the bee's knees.

TedP

+2 Yes!

[Ferris Wheels]

This would make an excellent steel for a full flat ground 8"-9" chef's knife. Now to go find a custom maker willing to go for it!

[Ankerson]

Ed, one question, since it's not totally clear to me from your posts. Is the cladding material Crucible's CPM-154 or is it 154CM made by Crucible? If the former, the jump from laminate to powdered metal damascus would seem easier, at least to my (mostly steel illiterate) mind and, given my fascination with Damasteel, that's something I'd find truly exciting.

It's CPM 154, not 154CM because they were concerned about blowing out the grain also.

[ABX2011]

When people talk about how a laminate steel increases toughness, are they referring to large blades like swords where the entire blade could crack? Am I wrong that for the purposes of cutting rather than chopping or prying or sword fighting - the laminate does not change performance at all?

[Ed Schempp]

Paul, this billet was prepared by putting a one inch thick piece of S90V between two equal layers of 154 CM powder. Then this billet is hipped, then rolled. So the final product is CPM 154 Cm, and double hipped S90 V. There may be some very slight benefit from double hipped S90 V.

I doubt that you will see any benefit to the double hipped S90V in cutting performance, but the laminate should be tougher an more ductile than homogenous S90V....Take Care...Ed

[Ankerson]

Paul, this billet was prepared by putting a one inch thick piece of S90V between two equal layers of 154 CM powder. Then this billet is hipped, then rolled. So the final product is CPM 154 Cm, and double hipped S90 V. There may be some very slight benefit from double hipped S90 V.

I doubt that you will see any benefit to the double hipped S90V in cutting performance, but the laminate should be tougher an more ductile than homogenous S90V....Take Care...Ed

Hi Ed,

I am thinking it should work really well in really thin ground blades that also need some flexibility also like in fillet knives, boning knives and really thin hunters for added toughness.

Jim

[Phil Wilson]

Ed, thanks for the history with Crucible, interesting. All I knew about it was I got a bar in the mail and an invitation to try it outl. I am finishing up a knife with it right now. I heat treated it like CPM S90v since to me I would rather have that grade's properties for wear resistance than make a compromise so as not to severely damage the CPM 154. So it looks like that worked so far. It is very hard to blow the grains in these CPM steels based on past experience. I have done some preliminary corrosion tests and the 90v of course is fine and no ill effects on the 154CM have shown up based on some salt water immersion overnight. I was a little concerned that the difference in alloy content would tend to make a battery effect but it just highlighted the departure line between the two. I need to send the knife to Crucible so they can examine it further. Why did they make it? I think just to see if they could and also as you say a step toward other combinations or a stainless damascus like ERA and Damasteel. It is "pretty," nice to work with-- and is easier to finish as intended. It would indeed make a very nice full flat grind Chef's knife. I made a scaled down South Fork this time. Cutting tests on rope indicate a very agressive blade. Maybe some result from the double hipping? I just hope it will be available in the future, even if the cost is pretty high. Phil

[Joshua J.]

At S90v you had my curiousity, and at damascus you had my attention. Sir, this is going to hurt my already empty wallet. Performance with style. And Phil Wilson, he knows some data. Now the next stop is k294 laminate?

I completely forgot about that.

If Crucible gets enough experience with clad steel, I have to wonder if the ultra high alloy steel types could be considered for production knives again.

[jabba359]

This thread needs pictures! :D

[Cliff Stamp]

Am I wrong that for the purposes of cutting rather than chopping or prying or sword fighting - the laminate does not change performance at all?

Aside from grinding/finishing it does two things :

-it lowers the set point force, meaning that the blade will bend and stay bent at a lower force

-it increases the set point angle, meaning the blade will bend and not crack off at a higher angle

This means that in very general, highly skilled/experienced guys are likely to see it as a negative but lower skilled/experienced people will see it as a positive (as they often put sets in their blades).

I heat treated it like CPM S90v since to me I would rather have that grade's properties for wear resistance than make a compromise so as not to severely damage the CPM 154.

Phil, what aus-temp are you using. 154CM has a very high tolerance for grain growth because of the temperature required to dissolve the Molybdenum carbide is above 2100 F. This is true even of ingot 154CM but even more so in the P/M version due to the greater dispersion of the M2C Molybdenum carbide.

[kbuzbee]

-it lowers the set point force, meaning that the blade will bend and stay bent at a lower force

-it increases the set point angle, meaning the blade will bend and not crack off at a higher angle

This means that in very general, highly skilled/experienced guys are likely to see it as a negative but lower skilled/experienced people will see it as a positive (as they often put sets in their blades).

Cliff, could you please explain your points further? All this bending and cracking of blades doesn't sound like knife use (the way I use them, anyway) unless I'm totally missing what you're saying here.

Thanks brother,

BTW - I'm loving this thread, my own confusion not withstanding. Just sitting in on a discussion between Jim, Ed, Phil and Cliff is the stuff of dreams

Ken

[Cliff Stamp]

Cliff, could you please explain your points further?

The original reason for laminates was basically because :

1) Steel was very expensive and hard to make and since the only part of the knife that cuts was the edge the rest of it could be anything even wrought iron (a popular choice).

2) The laminates were in general easier to machine, grind, finish

3) In extremes the laminates would keep the blade in one piece as they are near impossible to actually break

In general now the first one really isn't a practical issue and ironically laminates are more expensive now than a solid code steel aside from fairly extreme laminates (make a large chopper with a 121 Rex core and a 4340 cladding).

The second one is hard to argue unless the laminate is really different than the core, S90V/420J2. But when this is the case it will be quite dramatic for long term maintenance. Try to thin out the primary on a solid ZDP-189 blade for example and then on a ZDP/420J2 laminate.

The last is one of the common arguments for differential hardening which achieves the same thing in a different manner. Draw the spine and the blade will be much harder to break but easier to damage.

As an example I commonly get fillet knives to sharpen and they almost always have bent/warped blades. One of the main reasons for this is that the steels are very soft 3-5Cr13 class steels with a less than ideal HT which leaves them soft, and gummy (retained austenite and likely ferrite).

If those blades were instead solid S90V at 95% martensite (or similar class steels) then there would be less of them bent but some of them would be broken. In general the ones from the skilled guys would be fine the less skilled guys could break them from sloppy technique.