Low-Alloy, High Performance Knife Steels

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cm_bushman

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Oct 22, 2012
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I've been on a non-stainless kick lately, and while browsing around looking at some Japanese kitchen knives, I have started to look more closely at lower alloy and carbon steels. While I was looking at composition and correlating performance, one alloy that stuck out was Super Blue.

Super Blue, which (at 61.5HRc) has ranked very high in Ankerson's 5/8" rope test--in the same category as 60HRc Elmax and 65HRc ZDP-189--is a plain ingot steel with a maximum of 6% alloy, excluding trace sulfur and phosphorus (link at zknives). This is pretty good in my mind, considering Elmax is a 3rd generation powder steel with nearly 25% alloy (though it has superior toughness over Super Blue), and ZDP-189 has 20% Chromium alone, again with nearly 25% total alloy.

My question to you guys is what other steels are out there with low alloy that perform beyond what you would expect from their composition? Would 1095 , W2, or O1 put up similar numbers on an edge holding test if hardened up past 60HRc?
 
I grew up with the notion that carbon was far superior to stainless when it came to edge holding and ease of sharpening. That was the trade off for less corrosion protection. There's also a question of what defines edge holding. Some stainless steels take a "carpy" edge and hold it forever.
 
I'm a case CV lover, which is essentially 1095 with some extra chromium and vanadium, very easy to touch up and takes a hair whittling edge without to much effort.

(This is the composition of 1095, so Case CV will have a little more vanadium and chromium)

Carbon: 0.95
Vanadium : 0.19
Chromium: 0.45-0.48
Manganese: 0.40
Nitrogen: 0.03
Silicone p: 0.46
Copper: 0.46

2.97 percent alloy:thumbup:
 
PatrickKnight said:
Not sure about use in the kitchen but my knives in 52100 seem to hold an edge forever.
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I didn't mean to imply I was just looking at these steels for kitchen use, I'm looking for high performance in any application, as long as it's knives!

I have heard great things about 52100, but no have real experience with it. I've been itching to try it next to some of these new powder steels to see just how much of a performance increase you get with premium stainless.
 
If you really want to push the limits of true low-alloy steels with remarkable performance, you need to get tight with a maker who uses 1084. It really doesn't get any simpler than that, but it takes a pretty significant step up in alloying content/manufacturing processes to find a steel that truly performs better as a cutting implement. Corrosion-resistance and edge-holding are separate factors... but even when taking those into account, properly-HT'ed 1084 holds up pretty dang well.

A huge part of this is the simple fact that it has just enough carbon to get good and hard, but it also has a fine grain structure, so it's easy to get a really crisp sharp edge on it. 1084's toughness helps it keep that fine edge.

Carbon steels with a bit more alloy (O1, 52100, etc) are great for knives, too; don't get me wrong. But if you really want to get down to basics, get you some 1084 that's been forged/ground to a good geometry, and tempered to 58-60Rc (58 for big choppers, even as high as 62 for small thin slicers.) The performance will pleasantly surprise you.

(This is coming from a guy who mostly works with CPM-3V, CPM-154 and Elmax.)
 
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Thin Blade, edge geometry and High Hardness will increase performance over the more normal thicker blades and lower Hardness ranges.

But there is no magic process that will turn a simple carbon steel into CPM 10V.
 
parbajtor said:
I grew up with the notion that carbon was far superior to stainless when it came to edge holding and ease of sharpening.
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I never could wrap my head around this idea. How can something that's easier to sharpen also hold it's edge longer? Edge holding on most carbon steels is no where near high end stainless. My experience and others proves this out.

To the OP. I really like 52100(SR101) as well. I've heard a lot of japanese chef's knives are made out of it. Great steel.
 
cm_bushman said:
...Super Blue, which (at 61.5HRc) has ranked very high in Ankerson's 5/8" rope test--in the same category as 60HRc Elmax and 65HRc ZDP-189--is a plain ingot steel with a maximum of 6% alloy, excluding trace sulfur and phosphorus (link at zknives). This is pretty good in my mind, considering Elmax is a 3rd generation powder steel with nearly 25% alloy (though it has superior toughness over Super Blue), and ZDP-189 has 20% Chromium alone, again with nearly 25% total alloy.

My question to you guys is what other steels are out there with low alloy that perform beyond what you would expect from their composition? Would 1095 , W2, or O1 put up similar numbers on an edge holding test if hardened up past 60HRc?
Click to expand...

I am wondering why we are bringing the chromium content into a discussion of edge retention as if its contribution to the alloy content should mean something when the amount which would be tied up in carbides to improve wear-resistance is so low and the chromium carbides so much softer than the tungsten, molybdenum, and (esp.) vanadium carbides? That chromium is present to reduce corrosion, not improve wear resistance. However, reducing corrosion at a thin edge can GREATLY improve wear resistance if the environment/use eats away at the edge...

I guess what I am thinking is that wear-resistance isn't about the alloy content, it's about the carbide content - how much and how hard. Super Blue employs 2.5% tungsten to Elmax's 3% vanadium and requires an extra 1.5 RC to achieve the same wear resistance but lacks how much toughness and corrosion resistance in comparison?

Similarly, steel toughness is not about alloy content, it's about grain structure, specifically grain refinement - smaller grains of more homogenous distribution provide greater toughness (and are easier to machine). THAT is the advantage of the PM process - putting lots of high-wear carbide-forming elements into the matrix while retaining minimal grain size and homogenous distribution, so that wear resistance is vastly increased without unacceptable loss of toughness for a given application. Again, how tough is 61.5Rc Super Blue compared to 60Rc Elmax?

http://zknives.com/knives/steels/steelgraph.php?nm=Aogami Super, zdp-189, elmax&hrn=1&gm=0

http://www.crucible.com/eselector/general/generalpart1.html
 
chiral.grolim said:
I am wondering why we are bringing the chromium content into a discussion of edge retention as if its contribution to the alloy content should mean something when the amount which would be tied up in carbides to improve wear-resistance is so low and the chromium carbides so much softer than the tungsten, molybdenum, and (esp.) vanadium carbides? That chromium is present to reduce corrosion, not improve wear resistance. However, reducing corrosion at a thin edge can GREATLY improve wear resistance if the environment/use eats away at the edge...

I guess what I am thinking is that wear-resistance isn't about the alloy content, it's about the carbide content - how much and how hard. Super Blue employs 2.5% tungsten to Elmax's 3% vanadium and requires an extra 1.5 RC to achieve the same wear resistance but lacks how much toughness and corrosion resistance in comparison?

Similarly, steel toughness is not about alloy content, it's about grain structure, specifically grain refinement - smaller grains of more homogenous distribution provide greater toughness (and are easier to machine). THAT is the advantage of the PM process - putting lots of high-wear carbide-forming elements into the matrix while retaining minimal grain size and homogenous distribution, so that wear resistance is vastly increased without unacceptable loss of toughness for a given application. Again, how tough is 61.5Rc Super Blue compared to 60Rc Elmax?

http://zknives.com/knives/steels/steelgraph.php?nm=Aogami Super, zdp-189, elmax&hrn=1&gm=0

http://www.crucible.com/eselector/general/generalpart1.html
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The amount of chromium being tied up as carbides depends on heat treat. Technically it does depend on the alloy content because it has to have carbide forming alloys to even be able to make carbides.
 
Steel130 said:
The amount of chromium being tied up as carbides depends on heat treat. Technically it does depend on the alloy content because it has to have carbide forming alloys to even be able to make carbides.
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It depends on heat treat AND the other elements present, like tungsten/molybdenum/vanadium, as well as, um, iron and carbon which form, all by themselves (dpending on HT), austenite, martensite, ferrite, cementite - pearlite, bainite...

From what I've read, tungsten/molybdenum/vanadium all have higher affinity for carbide formation than chromium, and even if they had equal affinity the presence of these other elements quickly exhausts the carbon available to form carbides, again assuming a proper HT that forces them into solution.
 
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chiral.grolim said:
I am wondering why we are bringing the chromium content into a discussion of edge retention as if its contribution to the alloy content should mean something when the amount which would be tied up in carbides to improve wear-resistance is so low and the chromium carbides so much softer than the tungsten, molybdenum, and (esp.) vanadium carbides? That chromium is present to reduce corrosion, not improve wear resistance. However, reducing corrosion at a thin edge can GREATLY improve wear resistance if the environment/use eats away at the edge...

I guess what I am thinking is that wear-resistance isn't about the alloy content, it's about the carbide content - how much and how hard. Super Blue employs 2.5% tungsten to Elmax's 3% vanadium and requires an extra 1.5 RC to achieve the same wear resistance but lacks how much toughness and corrosion resistance in comparison?

Similarly, steel toughness is not about alloy content, it's about grain structure, specifically grain refinement - smaller grains of more homogenous distribution provide greater toughness (and are easier to machine). THAT is the advantage of the PM process - putting lots of high-wear carbide-forming elements into the matrix while retaining minimal grain size and homogenous distribution, so that wear resistance is vastly increased without unacceptable loss of toughness for a given application. Again, how tough is 61.5Rc Super Blue compared to 60Rc Elmax?

http://zknives.com/knives/steels/steelgraph.php?nm=Aogami Super, zdp-189, elmax&hrn=1&gm=0

http://www.crucible.com/eselector/general/generalpart1.html
Click to expand...


Of course you're right here, in the test I quoted (thanks Ankerson) Elmax is softer than Super Blue by 1.5Rc, not a negligible amount. At their respective hardness, the two alloys have similar edge-holding, but Elmax is (ostensibly) tougher by a good margin. Factor in corrosion resistance, and Elmax is arguably better in nearly every aspect that matters in a knife steel, though some may say Super Blue will take a finer edge and be easier to sharpen.

My point was not to deride high alloy stainless steels or to say that low-alloy steels are just as good or better than them, but merely to demonstrate that a nearly plain carbon (technically tool) steel could compare very favorably to a state-of-the-art powder stainless with 25% alloy. Chromium was brought up simply because it is a major alloying element, not to imply it was the greatest contributor to wear-resistance or carbide formation.

I'm a huge fan of high alloy, high carbide stainless and non-stainless steels like m390 (nearly 30% alloy), s90v (27.7% alloy), and M4 (a non-stainless with 21% alloy). Comparing them to steels like Super Blue (6% max alloy), it is simply fascinating that a "low-tech" ingot steel can compare so favorably, at least in edge-holding.

I also understand the geometry and HT can make or break a knife, no matter the steel used. Annealed 10v may not perform as well as properly heat treated 1084 at 60+HRc, but because of it's alloy , a proper HT will push 10v far beyond the limits of 1084.
 
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Well, there are even more basic Blue (with the same alloy elements as Super) and White (plain carbon) steels out there, Super Blue was just a well-known and tested example.
 
Professional heat treat O1 and 52100 will hold an edge longer than most people thought...from my experience, its just way much better than Busse's INFI steel.
 
shqxk said:
Professional heat treat O1 and 52100 will hold an edge longer than most people thought...from my experience, its just way much better than Busse's INFI steel.
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INFI wasn't designed to have high wear resistance. It's designed for high toughness. Many people here are pleased with its edge holding given how tough it is.
 
cm_bushman said:
Of course you're right here, in the test I quoted (thanks Ankerson) Elmax is softer than Super Blue by 1.5Rc, not a negligible amount. At their respective hardness, the two alloys have similar edge-holding, but Elmax is (ostensibly) tougher by a good margin. Factor in corrosion resistance, and Elmax is arguably better in nearly every aspect that matters in a knife steel, though some may say Super Blue will take a finer edge and be easier to sharpen.

My point was not to deride high alloy stainless steels or to say that low-alloy steels are just as good or better than them, but merely to demonstrate that a nearly plain carbon (technically tool) steel could compare very favorably to a state-of-the-art powder stainless with 25% alloy. Chromium was brought up simply because it is a major alloying element, not to imply it was the greatest contributor to wear-resistance or carbide formation.

I'm a huge fan of high alloy, high carbide stainless and non-stainless steels like m390 (nearly 30% alloy), s90v (27.7% alloy), and M4 (a non-stainless with 21% alloy). Comparing them to steels like Super Blue (6% max alloy), it is simply fascinating that a "low-tech" ingot steel can compare so favorably, at least in edge-holding.

I also understand the geometry and HT can make or break a knife, no matter the steel used. Annealed 10v may not perform as well as properly heat treated 1084 at 60+HRc, but because of it's alloy , a proper HT will push 10v far beyond the limits of 1084.
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Remember that test is with polished edges for general reference, the reason for the categories. :)
 
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