What are Matrix steels? YXR7, CPM-1V, Caldie, and More

[Larrin]

Matrix steels were first invented in the 1960s and then kind of forgotten. But they continue to have an effect on knife steels today. What are they? How were they invented? Which knife steels can be called “matrix steels”? Matrix Steels - YXR7, CPM-1V, Caldie, and More - Knife Steel Nerds

 

[ModRQC]

Cool!

 

[Nemo]

Thanks again Larrin for a very informative, interesting and well written article.

Apologies if I have missed it in your article, but have you seen any numbers for toughness of YXR7?

 

[Larrin]

Thanks again Larrin for a very informative, interesting and well written article.

Apologies if I have missed it in your article, but have you seen any numbers for toughness of YXR7?

Only Hitachi’s own numbers. https://www.hitachi-metals.co.jp/e/products/auto/ml/pdf/cwts_b.pdf

 

[ModRQC]

"Matrix high speed steel, extremely highest toughness in 62-65HRC. Available for vacuum quenching. Rolling dies, cold forging dies, roll, cold forging panches, blanking panches."

That and its presence across most high impact applications seem to say : as though as it can be in its category...

But barely better still than SLD when you get to the toughness charts.

 

[Larrin]

Looking at their u-notch data vs HAP10 the YXR7 is probably somewhere near CPM-M4 on my charts.

 

[LostHighway]

Thanks for this article (and all your work). To the extent that I understand the article I'm quite excited about the potential of some of these alloys for kitchen knives, especially for workhorse professional cook applications. Steels that can attain high hardness (63HRc+) while retaining good toughness aren't exactly plentiful. The added plus with these alloys is that they don't appear likely to be a bear to sharpen with conventional water stones. The wear resistance may be only adequate to good but if it rivals the Aogami 1 & 2, 1.2519, and 1.2442 that is certainly sufficient. I hope we will see micrographs and perhaps some edge retention testing. The huge caveat is price. Z-Tuff is available to knife makers but far from inexpensive. I can't recall having seen CPM-1V or ASP2012 listed from knife steels suppliers but then I haven't been looking for them.

 

[RDalman]

Thanks for this article (and all your work). To the extent that I understand the article I'm quite excited about the potential of some of these alloys for kitchen knives, especially for workhorse professional cook applications. Steels that can attain high hardness (63HRc+) while retaining good toughness aren't exactly plentiful. The added plus with these alloys is that they don't appear likely to be a bear to sharpen with conventional water stones. The wear resistance may be only adequate to good but if it rivals the Aogami 1 & 2, 1.2519, and 1.2442 that is certainly sufficient. I hope we will see micrographs and perhaps some edge retention testing. The huge caveat is price. Z-Tuff is available to knife makers but far from inexpensive. I can't recall having seen CPM-1V or ASP2012 listed from knife steels suppliers but then I haven't been looking for them.

https://www.erasteel.com/technologies/powder-metallurgy-asp/https://www.erasteel.com/wp-content/uploads/2020/06/GB_Grade_List_Summary.pdfEdit: They have rolling operations in Vikmanshyttan old steel mill here, so local to me

 

[LostHighway]

Thanks! My expertise is nil but I still enjoy speculating. I am not at all a fan of the super wear resistant, high carbide volume steels for kitchen knives. I think they answer a question that isn't worth asking, but PM alloys that have relatively fine grain, and can be pushed to high hardness while retaining very good to excellent toughness seem to me like an avenue worth pursuing.

 

[Larrin]

Powder metallurgy steels are never going to be as cheap as low alloy conventionally produced steel. Have to pull out the wallet for high end steel.

 

[LostHighway]

Powder metallurgy steels are never going to be as cheap as low alloy conventionally produced steel. Have to pull out the wallet for high end steel.

Understood, however, at least these less highly wear resistant steels probably don't impose the same costs in grinding/sharpening/finishing time and materials that something like Vanadis 4E or Z-Wear does (in the monosteel knives).

 

[Barmoley]

Thanks! My expertise is nil but I still enjoy speculating. I am not at all a fan of the super wear resistant, high carbide volume steels for kitchen knives. I think they answer a question that isn't worth asking, but PM alloys that have relatively fine grain, and can be pushed to high hardness while retaining very good to excellent toughness seem to me like an avenue worth pursuing.

You should try Z-wear class steels if you haven’t yet.

 

[LostHighway]

You should try Z-wear class steels if you haven’t yet.

I have a 180 gyuto in Z-Wear. I like the steel very much. It is the most wear resistant steel I've tried but SG2 and CPM154 would be the only even vaguely comparable steels that I have experience with. It is, however, the most time consuming to sharpen of the those three (SG2 laminated the other two mono).

 

[Barmoley]

I have a 180 gyuto in Z-Wear. I like the steel very much. It is the most wear resistant steel I've tried but SG2 and CPM154 would be the only even vaguely comparable steels that I have experience with. It is, however, the most time consuming to sharpen of the those three (SG2 laminated the other two mono).

You need better stones Jokes aside, there is a price to pay for better edge holding, so need to decide what is more important to you. Maybe Larrin’s new designed steel sharpens easier, time will tell, but preliminary reports are promising.

 

[LostHighway]

You need better stones Jokes aside, there is a price to pay for better edge holding, so need to decide what is more important to you. Maybe Larrin’s new designed steel sharpens easier, time will tell, but preliminary reports are promising.

I'm starting to think that what I'm chasing is sort of a better A2. I really don't have any issues with rust but the extra tolerance A2 provides relative to my iron clad knives is nice to have. I would appreciate a bit more edge retention and bit more toughness than A2 offers. CPM-154/RWL34, SG2/R2 and Z-Wear all have adequate or better edge retention and corrosion resistance. SG2 and CPM-154 probably both go in the wrong direction with regard to toughness. Also, none of those steels are IMO as pleasant to sharpen as A2.

 

[Barmoley]

I'm starting to think that what I'm chasing is sort of a better A2. I really don't have any issues with rust but the extra tolerance A2 provides relative to my iron clad knives is nice to have. I would appreciate a bit more edge retention and bit more toughness than A2 offers. CPM-154/RWL34, SG2/R2 and Z-Wear all have adequate or better edge retention and corrosion resistance. SG2 and CPM-154 probably both go in the wrong direction with regard to toughness. Also, none of those steels are IMO as pleasant to sharpen as A2.

Z-wear is better in every category than A2 except ease of sharpening, so just depends on how important that aspect is to you. Sounds like it is very important, so not a whole lot to be done, except maybe different stones and see how that works. A2 is a good steel too, but if you want better toughness and better edge retention, you have to compromise somewhere