[bob_loblaw]

If you look at White/Blue/Super funny they will rust. HAP40 is a high-speed tool steel. CPM M4 is a good comparison to it. MagnaCut will offer corrosion resistance that you don't tend to see in Japanese steels. MagnaCut will have better edge retention than White/Blue/Super. Those steels are low-alloy and rely on high hardness for wear resistance. MagnaCut has vanadium and niobium plus it can get pretty hard as well. MagnaCut is so far ahead of White/Blue/Super in this regard. Japanese steels are known for being great to sharpen (even HAP40). From what I have read, MagnaCut sharpens well.

If we say that MagnaCut = stainless 4V and HAP40 = CPM M4, then HAP40 should have some more edge retention but less toughness when compared to MagnaCut. The differences aren't all that great. Corrosion resistance is the real difference maker.

[namibj]

Do you know how tungsten carbide with nickel binder stacks up in comparison? The usual cobalt binder of course isn't that good in terms of corrosion resistance, but for e.g. vegetable knife purposes, sharpness is very much required, toughness only so much as a brittle blade shatters if you look at it funny, and edge retention determines whether you have to (learn to) sharpen it at location, or can transport it to a service center.

[bob_loblaw]

It is hard to make comparisons like this. I know that is a crappy answer. But geometry by far the most important characteristic. How thick is the overall blade stock? How thick is the knife behind the edge? Those two things will matter more than steel composition. Then you have heat treat. A great steel with a crappy heat treat is going to make for a lackluster knife.

But, regarding tungsten. There is a steel called Maxamet, and it is used in several knives by Spyderco. It should be noted that I am a Spyderco fanboy, so take my recommendation of this company with a grain of salt. I like them more than any other production knife company, perhaps to a fault. Anyways, Maxamet is run really hard, like 67 HRC. Most production companies will run their knives in the upper 50's so the knives roll instead of chip. Quality production companies (Spyderco, Benchmade, Hinderer, Chris Reeve, etc.) will run most of their steels to around 59-60 HRC. Maxamet can cut for a long, long time. This steel has 2.15% iron (which helps with attaining a higher hardness), 10% cobalt, 13% tungsten, and 6% vanadium. I can't think of another steel used in cutlery with as much tungsten as Maxamet. The cutting numbers from this steel are near the top of the charts. So Maxamet will blow MagnaCut out of the water when it comes to edge retention, but it was designed as a high speed tool steel. MagnaCut was designed to be a "jack of all trades, master of none". Steels like Maxamet require skill and some special tools as a sharpener. It's all about choosing the right steel for the job. Often tradeoffs are involved.

Steel chart - https://www.spyderco.com/edge-u-cation/steel-chart/

I will say that hard, thin knives have a reputation for chipping. Triple B Handmade Blades is a custom maker that focuses on maximizing cutting performance. So he uses high-carbide, high hardness, thin (like crazy thin) edges. You would think that his knives would shatter, but they do surprisingly well in his testing. Here's a short video of Rex 121 (has the highest percentage of carbide volume) heat treated to over 70 HRC. He is performing twisting cuts with a hard wood. At the end, the knife still cleanly cuts paper. You don't see/hear any chipping.

https://www.youtube.com/watch?v=xAPMXGvrJ1I

[namibj]

Well, I was comparting to/with something like Durit's GD20N [0], which scores 1400 HV30 which should be like 83.6 HRC or thereabouts. It's a WC-Ni powder metallurgic composite with 9% binder. Their website suggests that they make blades for industrial paper cutters, but I'd assume those use normal WC-Co due to paper not being particularly corrosive.

Sure, the geometry matters a lot, but that's also fairly orthogonal from the metallurgy.

[0]: https://www.durit.com/en/technology/carbide#c1340

[bob_loblaw]

That's an interesting material. I'm not a knife maker so I can't really answer your question. I would imagine that this material would, initially, pose a problem for large-scale production. You would have to learn how to work with this material as it is not steel. Their current set of tools and techniques probably won't work well with a fundamentally different material.

If anybody were to try this, I would suspect that it would be easier for a customer knife maker to do so. Kase Knives[1] has messed around with elastic ceramic before. He's always pushing boundaries. He might try something like what you suggested.

It would be incredibly expensive though. I wonder if you could laminate some slabs of mild steel around a carbide core. This is done with steel all the time (especially in Japan). Not sure you could do this with steel and carbide though. You only really need enough carbide to form the apex. The rest of the blade stock is there for lateral strength.

[1]https://www.kase-knives.com/home/english/