Stainless vs carbon steels: toughness and edge retention - what am I missing?

[Barmoley]

I agree apart from toughness Magnacut will outperform AEB-L in everyway, but my point was the different heat treatment by makers could result in vastly different experience. For example one maker's Aogami super last longer than other's VG10 at 60 HRC, while in theory it shouldn't be. I'm comparing steels supposedly more close to each other, so high alloy is not always better than low alloy in some experience. Of course if we count in steel like Magnacut, M390 or Hap40 they are going to be significantly long lasting than any low alloy, but not all high alloy is going to behave that way.

I don’t disagree with any of it. Ofcourse different heat treats make a difference. Different geometries also make a huge difference. You can’t compare steels like that. You can compare knives and say that some low alloy knife cuts better and longer than some high alloy knife. You just can’t generalize knife performance to all the knives made out of the same steel amd then conclude that one steel is ”better” than the other. I hope that by now with all the effort that was made by people in the community it is clear that in order to compare steels themselves in the least all the knives have to be the same in everything else.

 

[blokey]

I don’t disagree with any of it. Ofcourse different heat treats make a difference. Different geometries also make a huge difference. You can’t compare steels like that. You can compare knives and say that some low alloy knife cuts better and longer than some high alloy knife. You just can’t generalize knife performance to all the knives made out of the same steel amd then conclude that one steel is ”better” than the other. I hope that by now with all the effort that was made by people in the community it is clear that in order to compare steels themselves in the least all the knives have to be the same in everything else.

I think we are saying the same point but in a different way. What I was saying is exactly “You can compare knives and say that some low alloy knife cuts better and longer than some high alloy knife. You just can’t generalize knife performance to all the knives made out of the same steel amd then conclude that one steel is ”better” than the other.” Because people tend to generalize all high alloy steel knives is better than low alloy steel knives, which is not true.

 

[captaincaed]

Lowish grit diamond. Cut tomatoes all day. At least that's my experience with Z-wear. Which I'd assume would be more like MagnaCut, than AEB-L.

For sure. That’s similar to my experience. I have this goofy second hand 500/3k sankyo diamond stone that actually puts great edges on, but smells like a tire factory.

For me and high alloy steels, I don’t have great luck getting 4-6k edges last that long with the tooth I like. I can get that reliably with most simple carbon and basic tool steels. Who knows. Maybe I need to try Harbeer’s Zwear.

 

[Troopah_Knives]

technically Z-wear is also carbon steel

In the field of tool steel I usually see stuff broken down as follows not that we have to use the same framework. But it might help clarify things if we all are speaking the same steel language

1. Carbon steels (C+Mn sometimes a small V addition)
2. Low alloy steels (Cr <2ish% )
3. Medium alloy steels (2%<Cr<4%)
4. High alloy steels (Cr >4%)
   1. non-stainless
   2. stainless

Carbon vs stainless is so vague it is meaningless.

see above maybe defining it that way helps with vagueness.

For example one maker's Aogami super last longer than other's VG10 at 60 HRC, while in theory it shouldn't be.

Again as I have said before. I really don't like ascribing quite so much value to HTs. Heat treating is a fairly simple process so I think most of these differences are really geometry.

Compared to food, even pedestrian iron carbides are pretty hard.

I mean to be fair compared to food and steel or even any metal is pretty hard. So I don't think that this idea can be used to discount harder carbides

I think I like is small-carbide size

I'm a little confused here as above you say that you like A2 which has pretty large carbides and that you don't like magnacut which has carbides similar in size to AEB-L.

high alloy steels

Do you mean high alloy steels or high alloy steels with MC (V W Nb etc) type carbides? Do you have diamond 4-6k stones?

 

[captaincaed]

I’m not really sure why my post yielded so much confusion. Was it read in some other spirit besides “I’m drinking a cocktail and waxing nostalgic”?

 

[mengwong]

Thumbs up from me on writing style, 10/10! May the booze flow as freely as your words.

 

[captaincaed]

I'm a little confused here as above you say that you like A2 which has pretty large carbides and that you don't like magnacut which has carbides similar in size to AEB-L.

A2 certainly has larger inclusions. On average, seems like it can be made fairly fine. D2 is my arch-nemesis. Several folders I just don’t enjoy sharpening.

No idea if carbide size is why I don’t enjoy sharpening magnacut, happy to revise my opinion. This is an “on average” observation/speculation.

 

[Troopah_Knives]

A2 certainly has larger inclusions. On average, seems like it can be made fairly fine. D2 is my arch-nemesis. Several folders I just don’t enjoy sharpening.

It has a pretty low carbide volume while it looks like it is finer then SG2 the average carbide size is a bit larger. It has a pretty small volume of micron-ish carbides like AEB-L and some very large 10+ micron carbides while the larger carbides in SG 2 are more like 5 microns. I guess it depends on what you mean by on "average it can be made fine".

 

[Deadboxhero]

A couple of points:
1. Assuming silica is the dominant abrasive in food all steels will dull in this way except i. low alloy steels with <0.9% C ii. C-Mn steels (White steels)
2. If it there is some softer abrasive then only i. would not dull in this way.
3. It's certainly plausible that Micro-serrations have something to do with CATRA performance but I don't think that has been proven.

My point with these is that if what you are saying is true it just means that the small subset of very low alloy steels (low alloy with no W V and <1% Cr) might be an exception to the testing. I see no reason to assume that CATRA isn't a valid test of wear resistance vs a Silica test medium.

Anyway, I think you are right about most of what you said especially with the hardness pt above I just wanted to address the above point because it stuck out to me.

Well it could also be the front end sharpness is mostly due to matrix which doesn't last and wears away quickly.

There's nothing stopping anybody from doing other testing outside of CATRA.

I was curious myself if there was a way to see front end sharpness retention with specialized testing to look at the loss of sharpness with the first initial cuts using a bess and logarithmic recording.


Well within the first 25 cuts we didn't see much separation in sharpness measured in grams

I expected the 52100 to do better, but they were all basically the same within scatter under 25 cuts. Afterwards we saw separation when the harder carbides at higher volume supported by harder matrix took over, the carbides simply weren't present to prevent the 51200 from wearing smooth.

That means what we are seeing with everybody's scattered anecdotal accounts is mostly just folk's sharpening idiosyncrasies.

Some folks are just putting better edges on some knives than others. Some abrasives will cut some steels better than others. Some steels will deburr with less attention to detail better than others.

Well from what I saw it didn't deviate much from CATRA.

If all things are equal, higher hardness with higher volume of the hardest carbides was dulling less even at the front end.

 

[esoo]

Well it could also be the front end sharpness is mostly due to matrix which doesn't last and wears away quickly.

There's nothing stopping anybody from doing other testing outside of CATRA.

I was curious myself if there was a way to see front end sharpness retention with specialized testing to look at the loss of sharpness with the first initial cuts using a bess and logarithmic recording.


Well within the first 25 cuts we didn't see much separation in sharpness measured in grams

I expected the 52100 to do better, but they were all basically the same within scatter under 25 cuts. Afterwards we saw separation when the harder carbides at higher volume supported by harder matrix took over, the carbides simply weren't present to prevent the 51200 from wearing smooth.

That means what we are seeing with everybody's scattered anecdotal accounts is mostly just folk's sharpening idiosyncrasies.

Some folks are just putting better edges on some knives than others. Some abrasives will cut some steels better than others. Some steels will deburr with less attention to detail better than others.
View attachment 212762

Well from what I saw it didn't deviate much from CATRA.

If all things are equal, higher hardness with higher volume of the hardest carbides was dulling less even at the front end.View attachment 212763

Excellent information.

Just out of curiosity: is the rope cut in free air or against a board?

Not that I'm asking for this to be done, but I'm curious what would happen with a similar test if the rope was saturated in lemon juice. I would expect similar results, but curious how the the spread would change if there was an acidic component as that is common in kitchen cutting tasks.