CPM S110V still up there?

That's a pretty old chart that predates some of the better catra testing data available- this would be a little more accurate (although it is due for a few updates with new testing data). I actually think there was a mistake with Maxamet in that old chart.
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Thanks for the update. Can’t have too much new data!
 
That's a pretty old chart that predates some of the better catra testing data available- this would be a little more accurate (although it is due for a few updates with new testing data). I actually think there was a mistake with Maxamet in that old chart.
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It looks like CPM-154 and 154CM might be reversed on that chart. I would expect the higher toughness from the CPM steel over the ingot.
 
I'm not sure what you mean by tentative. The steels that are used for knives have heat treatments and hardness ranges that have almost universally been optimized for knives. There are some "special" heat treatments that claim to improve some steels in knife use, but they are rare.

Hardness does generally improve edge retention when you are comparing the same steel if toughness/edge stability doesn't fall too far down in a particular heat treatment, in which case edge retention will also suffer at that point. If you compare different steels, hardness is not a major factor. Steels that have a high carbide volume at high 50's HRC will almost always have significantly better edge retention than more basic low carbide steels at low to mid 60's HRC for example.
My 20 year EDC in ZDP-189 gets most of its wear resistance from its 67HRC rating. My other 15 year EDC in Stellite 6-K gets most of its wear resistance from included Chrome and Cobalt Carbides. Even though the blade Rockwells in the mid 40’s, a file won’t touch it.View attachment 2088132
 
My 20 year EDC in ZDP-189 gets most of its wear resistance from its 67HRC rating. My other 15 year EDC in Stellite 6-K gets most of its wear resistance from included Chrome and Cobalt Carbides. Even though the blade Rockwells in the mid 40’s, a file won’t touch it.View attachment 2088132

There are no cobalt carbides,
Stellite 6K is 25% volume of chromium carbides in a cobalt matrix at 46 HRC

SEM by Zhang 2014



Screenshot_20230218-200852.png
 
Thanks for the clarification. The material is so wear resistant that they make cutting tools out of it and put it on the edge of bulldozer blades.
It's an interesting material but I think that the PM tool steels have it beat with harder carbides and a harder matrix.
 
I prefer it to my S90, S110, S125, and Rex 121.
I'm a fan of ZDP 189 myself, but the majority of the wear resistance is from the 30%+ carbide volume which is higher than the vast majority of PM steels out there.

If you compare it with it's peers in edge retention, ZDP has a significantly higher carbide volume to most of them. Most of the others that are lower on the carbide volume use harder carbides such as vanadium carbides though which even up the playing field even though the overall volume of carbides may be lower.

On the flip side, you can compare ZDP at mid to high 60's HRC to something like Shirogami White #1 or Aogami Super and the edge retention(or carbide volume) isn't close.
 
And so,, as advertised, Magnacut is in the middle of the curve ("balanced" as they all say). Compared to other steels, it charts out as moderately tough with moderate edge retention.

What would it take to bring forward a steel formulation that has a data point both up and to the right of Magnicut?

I am sure that some materials scientist is staying awake nights thinking about that.

I am also sure that if it could be done today it would have been done yesterday!
 
I'm a fan of ZDP 189 myself, but the majority of the wear resistance is from the 30%+ carbide volume which is higher than the vast majority of PM steels out there.

If you compare it with it's peers in edge retention, ZDP has a significantly higher carbide volume to most of them. Most of the others that are lower on the carbide volume use harder carbides such as vanadium carbides though which even up the playing field even though the overall volume of carbides may be lower.

On the flip side, you can compare ZDP at mid to high 60's HRC to something like Shirogami White #1 or Aogami Super and the edge retention(or carbide volume) isn't close.
I wasn’t very clear in stating my preference for Stellite 6-K over super steels, but I also like the sharpenability of ZDP-189 in the absence of Vanadium.
 
And so,, as advertised, Magnacut is in the middle of the curve ("balanced" as they all say). Compared to other steels, it charts out as moderately tough with moderate edge retention.

What would it take to bring forward a steel formulation that has a data point both up and to the right of Magnicut?

I am sure that some materials scientist is staying awake nights thinking about that.

I am also sure that if it could be done today it would have been done yesterday!

This is true for edge retention but toughness is actually quite good compared to steels in the same ballpark for edge retention. Are any steels tougher for the same level or even one step below on edge retention?

It is also near the top for corrosion resistance. So overall, I wouldn't call MagnaCut "middle of the road".
 
Not knocking Magnicut. I understand that it is a good knife steel. Early proponants described it as "balanced" in performance.

My post was intended to be a musing on metallurgy and materials science as they relate to cutlery steels. . . . and wishful thinking too.
 
This is true for edge retention but toughness is actually quite good compared to steels in the same ballpark for edge retention. Are any steels tougher for the same level or even one step below on edge retention?

It is also near the top for corrosion resistance. So overall, I wouldn't call MagnaCut "middle of the road".
Where it is ground breaking is in corrosion resistance in relation to the other attributes. There are similar performing steels if you discount the corrosion resistance.
 
Where it is ground breaking is in corrosion resistance in relation to the other attributes. There are similar performing steels if you discount the corrosion resistance.

Like I asked above, are any steels tougher for the same level (or even one step below) on edge retention?

For reference, here is Larrin's rating chart again. MagnaCut has a 5 in edge retention and a 7 in toughness. Of all other steels rated 3.5 or higher on edge retention, none of them achieve a toughness rating greater than 5.

9bf29b8c-ca75-4663-ae1f-709a4d3e1d85-jpeg.2053724
 
I think he's talking about tool steels. They are not very corrosion resistant but do match the toughness/edge retention of magnacut (4V and M4 are close). But the achievement of having a very stainless steel match the performance of high alloy tool steel is amazing in itself.
 
Like I asked above, are any steels tougher for the same level (or even one step below) on edge retention?

For reference, here is Larrin's rating chart again. MagnaCut has a 5 in edge retention and a 7 in toughness. Of all other steels rated 3.5 or higher on edge retention, none of them achieve a toughness rating greater than 5.

9bf29b8c-ca75-4663-ae1f-709a4d3e1d85-jpeg.2053724
Well yes, 3V has better toughness and similar edge retention.
 
I think he's talking about tool steels. They are not very corrosion resistant but do match the toughness/edge retention of magnacut (4V and M4 are close). But the achievement of having a very stainless steel match the performance of high alloy tool steel is amazing in itself.

Indeed. The achievement is not just in doing that with a stainless steel but one of the most stainless blade steels.
 
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