Devin makes some great damascus patterns.
For me personally, I'd confine Devin's *stainless* damascus to bolsters or handles or handle inlays, etc, or to the blade of an "art" knife that won't be used to cut anything (or much of anything).
Devin's carbon/carbon damascus should perform like any other carbon steel if the maker heat treats it correctly. His carbon/nickel should be lower on edge holding scale than carbon/carbon, but it will take a great looking, high contrast etch.
Devin's stainless damascus is made of AEB-L and 304SS. Fritz Schneider (beautiful steel) also uses something similar to AEBH or AEBL and a 300 series. So did Hubbard (deceased).
AEBL is about 440A or 440B in terms of metallurgy, it may have less chrome (I can't find a compositional run down on AEBH). 304SS is not martensitic, it is austenitic, i.e. it won't harden. The 300 series stainless steels do NOT make good knife blade steels what-so-ever. But the 300 resists ferric chloride etch so you get a nice pattern.
You mix AEBL and 3xx and you have something less than 440A or 440B in terms of edge holding. I believe that decarburization will pull carbon out of the AEBL and into the 300 series matrix, thereby lowering the overall carbon content of the AEBL, which lowers the ultimate hardness level. How much? Could be by a couple points on HRC and that can be substantial in terms of edge holding. Beowulf's post indicated that Devin's SS damask would harden to about Rc55, maybe Rc57 with the right batch in the right hands. This is well below the Rc59-60 that is very much commensurate with top edge holding in general (ignoring 440V at 56-58 for now).
But it sure looks good. I love the look of damascus, but I don't expect stainless damascus knives to cut particularly well... and that is my only point.
Moving up on the SS damascus cutting performance scale, Mike Norris uses AEBH, D2, and 300 series stainless...3 materials. His stainless seems to outcut most all others except maybe Damasteel, because he has D2 in the mix (1.1% vanadium and more carbon to mitigate the effects of decarburization, D2 starts at 1.4-1.6% Carbon).
Damasteel uses a powder metallurgy process to combine what is essentially a near ATS-34 clone called RWL 34 (1.05%C 14%Cr 4%Mo) and a steel called PMC 27 (0.60%C 13.5%Cr is all they say about it, close to 12C27) so it is somewhere in the AUS-6/440A/12C27 range. These should combine to make a steel that is, well, somewhere in between. I find my Damasteel blade takes a good toothy edge and holds it fairly well with a Darrel Ralph heat treat. Not bad, looks pretty good. Damasteel doesn't really give you an etch where you can "feel" the layers with your finger... it always seems to end up smooth, I think mostly because the mixture is homogeneous powder that is compressed, not layers welded together in a press or under a hammer. The layers aren't as distinct...they seem to bleed together a bit. With Norris' steel, you can actually see and feel the layers... more character, more substance.
Don't fall too hard for the "damascus cutting effect" info out there. Some knowledgeable people have written that really only a tight ladder pattern even begins to show this sort of "alternating steel, mini sawtooth" effect. You are going to do even better than this mild effect if you use diamond or other medium stones to finish your final edge to a "toothy" grabby edge, if you prefer such edges (I do).
In very general but very valid terms, anything easy to sharpen is going to be easy to unsharpen... i.e. easy to wear down the edge.
Mike Norris does do a "San Mai" styled damascus....I believe he starts with his regular ss damascus (D2, AEBH, 304) and then wraps that around a 440V core. He apparently is experimenting with a 420V core. I bought two custom hunting knives 2 years ago out of Mike's San Mai SS damascus with 440V core, and while they hold an edge very well, I would guess a pure 440V blade well heat treated would do better. I should compare them side-by-side on rope someday, and intend to.
The San Mai damascus with a "good steel" core is an excellent compromise between edge holding and beauty, and when it catches on and people learn how to heat treat it right, I hope Mike can ramp up production and make some money providing such great stuff to the public. I'm impressed with Mike's ability and innovation, since he seems to keep his eye on the "edge holding" ball. Kudos.
That Arthur Washburn post is excellent (BeoWulfTheGeat). I saved it for reference.
One note: the guys at Crucible who say "sub zero does little for knife blades" are referring to sub zero on their 420V and 440V steels I believe. That's what they told me at Guild. They did tell me, as did Darrel Ralph, that sub zero does help other stainless tool steels like ATS-34, 154CM, 440C, D2, and higher end carbons like 52100, but just has less effect on the CPM420V/440V stuff. I would surmise that the basic characteristics of 420V/440V in quench just leave less retained austenite, so the sub zero has less it can convert to martensite compared to the other steels.
[This message has been edited by rdangerer (edited 02-04-2001).]
