Why so stainless?

shqxk said:
AEBL has only 0.66% carbon with 13% Cr so it would never be the same as hypereutectoid carbon steel like 52100(Bohler's R100) which has 1%C and 1.5Cr. The structure matrix of both would be totally difference.
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Testing of, and micrographs of those steels at the same hardnesses bely your claims. They are NOT totally different at all, in practice at knife-size sections and hardnesses... the only demonstrable difference in actual knife blades is, AEB-L has a whole lot of free chrome that adds corrosion resistance, 52100 does not. That's exactly what it was designed for, nearly a century ago.

shqxk said:
AEBL has only 0.66% carbon with 13% Cr so it would never be the same as hypereutectoid carbon steel like 52100(Bohler's R100) which has 1%C and 1.5Cr.
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Of course AEB-L is not hypereutectoid, that's the whole point behind its chemistry. It has a little more carbon than is required to reach 62Rc in austenization, with almost no carbon left over to form carbides with the chrome. With deep cryo, it can reach somewhat higher hardnesses. Nearly all the chromium is free - hence, high corrosion resistance without sacrificing the toughness inherent in a "simple" euctectoid steel.

52100 has twice the carbon and a touch of chrome and a signifigant amount of manganese - not for carbide formation, but specifically for deep-hardening and hot-hardness; meaning it stays hard under pressure/heat/friction. Because it was designed for bearings, not fine-edged cutting implements.

Your understanding of how steels harden, and how carbides form, and why that would be good for one tool or another, seems to be deeply flawed. The notion that more carbon automatically makes a more resilient, tougher, or finer edge is simply not true. If that were true, highly-alloyed steels like CPM-154 and Elmax and XHP would be way, way better because they have even more carbon... and cast iron would be the best of all. But that's just not how it works.

Do yourself a favor and look up lathe vs. plate martensite, to start with.... before you even consider carbide formation and how alloying elements affect HT responses.

We're getting into the territory of side-stepping data and talking louder to obscure facts. I'm disappointed, but not particularly surprised.
 
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Even 0.2% carbon can make a vast different on steel. 5% chrome can change steel from shallow/water hardening to deep/air hardening.

Now you say 13% chrome would not make a much different... seriously?
 
I don't understand how 13% free chromium dispersing into the matrix replacing martensite structure would not make any different.

Some amount of Cr could increase toughness/strength and hardenability, very minor amount of Cr could help in pin grain boundary in austenite phase.

But when Cr reach amount that give steel stainless property, it high likely to reduce the overall toughness of structure. Since free chromium structure itself are much weaker compare to tempered martensite and also the increasing of the K1 carbide can cause fracture at grain boundary.
 
I just read the back and forth about testing, and it really put the problem of comparing steels in greater perspective:

You can't really make two knives in two different steels with the same geometry and cut only one thing. The only conclusion you reach is that those steels performed differently when made the same way and tested on that one thing.

There may well be an ideal combination of heat treat, edge geometry, hardness and cutting task for every alloy. That alloy could certainly perform well at other tasks, hardnesses, etc - but until you've determined that W2 (say) really excels when carving hardwoods at a 23 degree edge and 60 Rc, you aren't going to be able to begin making any sort of real comparisons, because you don't even know what else acts in a similar manner.

I'm certain I'm preaching to the choir, but all the reading I've done recently just about D2 leaves me deflated. Experts seem to have opinions that are polar opposites about tempering temps. How can this kind of thing still be such a source of debate for a steel that predates WWII????

A poster on a recent thread felt that CPM 154 and 154CM were "the same thing", not just because they were the same alloy, but because his CATRA tests showed they acted the same. How did that happen????

I would love to see knife cutting tasks (rather than die or slicer tasks) broken down by the demands they place on edges, because knives do not just slice. I would like to see heat treatment results expressed in graphs that depict edge stability, hardness, toughness and wear resistance in such a way that their confluences and discontinuities become obvious. And I would like to ideal knife heat treatments replace tool and die heat treatments on spec sheets intended for cutlery.

Until a little consistency starts to eek its way into knife metallurgy, these kind of discussions will continue to be witchcraft. The more I read, the more convinced I am that heat treating and alloying is still a relatively crude and haphazard process where the final results for two knives of the same alloy and design might behave so differently that they might as well have been completely different alloys.

I don't know whether the problem is people not sharing what they learn, or other people not believing them because they don't have the skill to repeat results, or alloy lots varying too much to control heat treat to the right degree, but I would not be shocked to find out that someone's W2 knife did actually perform the most cutting task better than any other alloy. We don't seem to understand the full scope of the question to come up with entirely satisfactory answers.
 
Jamesh Bond said:
I like carbon. I would take 1090 over S30v any day.

Despite the advances in modern stainless, I still havent found any of it to even come close to the combined edge retention and ease of sharpening of simple carbon. This is unfortunate considering all but one of my knives are stainless. I do really love them, but they could be be even better. Why the predominance ???

The MAIN reasons i can see are:

Folders. Less worry about corrosion problems in the not so easy to reach parts. Weak argument. But i guess i can see it. And why even go there on a fixed blade?

Sales. Form over function. Shiny = better. And new formulas and super steels to pitch, along with justification of high cost.

Environment. If you live in a jungle by the ocean, i can understand choosing say, H1. Still a weak argument. Carbon steel machetes have been the go-to in these places forever. Take care of your crap.

Notice, the only reason i cant really argue with is the second one.

So yeah, while i get satisfactory performance from my stainless knives, there is always that nagging annoyance in the back of my head reminding me that i had to compromise to own a given blade. That they could be better. It would be awesome if i could get a spyderco, kershaw, or cold steel folder in 1095 or whatever.

To each their own, and its cool to have so many choices, but factories that dont offer the option are limiting themselves and their customers.

I would like to get my bias shifted. Hoping to see lots of reasons i havent considered.

Thoughts?
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I like carbon steel for a variety of reasons, it's incredibly tough, holds an edge better then most stainless steels, and is very easy to sharpen. In my experience however, 1095 doesn't have the edge retention of s30v. It's a whole different class. I would definitely buy folders made of 1095 or d2 or any other carbon steel though.
 
yepimonfire said:
I like carbon steel for a variety of reasons, it's incredibly tough, holds an edge better then most stainless steels, and is very easy to sharpen. In my experience however, 1095 doesn't have the edge retention of s30v. It's a whole different class. I would definitely buy folders made of 1095 or d2 or any other carbon steel though.
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Why would you choose 1095 over W2, O1, 52100 or A2?
 
james terrio said:
Your understanding of how steels harden, and how carbides form, and why that would be good for one tool or another, seems to be deeply flawed. The notion that more carbon automatically makes a more resilient, tougher, or finer edge is simply not true. If that were true, highly-alloyed steels like CPM-154 and Elmax and XHP would be way, way better because they have even more carbon... and cast iron would be the best of all. But that's just not how it works.

Do yourself a favor and look up lathe vs. plate martensite, to start with.... before you even consider carbide formation and how alloying elements affect HT responses.
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I never said that higher carbon always lead to better edge holding, in fact all I said are totally opposite to what you had sum my word up since I said carbon steel which has lower C (Bohler's R100) hold an edge better than S30V from my test.

I understand if AEBL could have capability to hold low angle/razor edge better than most steel since it has exactly amount of alloy to do so. From what I study this steel likely to form minor amount of K2 carbide which are super fine and might aid the very small edge apex, while having rest structure as lath martensite.

But this could be the same to eutectoid steels like 1084 or SK5. But different are carbon steel likely to has much more complete and stiff martensite structure (much less likely to have any retained austenite)compare to AEBL due to the quench rate.
 
By all means, do not overlook the deep-freeze. Welcome to it.
 
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james terrio said:
By all means, do not overlook the deep-freeze. Welcome to it.
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I will appreciate any principled education from you James, Ankerson and whoever.

I love metallurgy even before I entered this forum. Anyone could have difference opinion and experience. I apologize to you and mister Ankerson if my word sound offensive but hey English isn't my first language.

I have learnt so much from here and I don't want anyone to blow up at me.
 
RX-79G said:
I just read the back and forth about testing, and it really put the problem of comparing steels in greater perspective:

You can't really make two knives in two different steels with the same geometry and cut only one thing. The only conclusion you reach is that those steels performed differently when made the same way and tested on that one thing.

There may well be an ideal combination of heat treat, edge geometry, hardness and cutting task for every alloy. That alloy could certainly perform well at other tasks, hardnesses, etc - but until you've determined that W2 (say) really excels when carving hardwoods at a 23 degree edge and 60 Rc, you aren't going to be able to begin making any sort of real comparisons, because you don't even know what else acts in a similar manner.

I'm certain I'm preaching to the choir, but all the reading I've done recently just about D2 leaves me deflated. Experts seem to have opinions that are polar opposites about tempering temps. How can this kind of thing still be such a source of debate for a steel that predates WWII????

A poster on a recent thread felt that CPM 154 and 154CM were "the same thing", not just because they were the same alloy, but because his CATRA tests showed they acted the same. How did that happen????

I would love to see knife cutting tasks (rather than die or slicer tasks) broken down by the demands they place on edges, because knives do not just slice. I would like to see heat treatment results expressed in graphs that depict edge stability, hardness, toughness and wear resistance in such a way that their confluences and discontinuities become obvious. And I would like to ideal knife heat treatments replace tool and die heat treatments on spec sheets intended for cutlery.

Until a little consistency starts to eek its way into knife metallurgy, these kind of discussions will continue to be witchcraft. The more I read, the more convinced I am that heat treating and alloying is still a relatively crude and haphazard process where the final results for two knives of the same alloy and design might behave so differently that they might as well have been completely different alloys.

I don't know whether the problem is people not sharing what they learn, or other people not believing them because they don't have the skill to repeat results, or alloy lots varying too much to control heat treat to the right degree, but I would not be shocked to find out that someone's W2 knife did actually perform the most cutting task better than any other alloy. We don't seem to understand the full scope of the question to come up with entirely satisfactory answers.
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The main problem is that the knife industry makes up around 10% or less of the steel industry as a whole.

So things do have a long way to go and as you pointed out the data sheets are typically tailored for tool and die applications, not knife blades so most of the typical data like toughness etc is for the most part useless when talking about knife blades.

Start factoring in the variations from run to run of the steels (Batches), they do vary.

With that said we haven't even started talking about the variables in HT, geometry, edge finish etc in a knife blade.

It's not witchcraft, there are so many variables working in the whole process that it can be mind boggling.

Then factor in the human elements... :eek:


So that's why my answer to questions will usually be "it depends".
 
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Ankerson said:
I have a few of Chris's knives in the rankings as some others. :)

He just hasn't got around to sending me any 3V yet.
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I managed to find your test thread (I was too tired to find it last night) and I am very impressed how many more cuts his knife in cmp-4v did than the long list of production knives below it.
 
155440 said:
I managed to find your test thread (I was too tired to find it last night) and I am very impressed how many more cuts his knife in cmp-4v did than the long list of production knives below it.
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Chris makes a good knife, he knows how to make them perform. :thumbup:
 
There is a long way to go from a bar of steel to a knife blade.

DSC_5149.JPG
 
Sunyata said:
Personally?


I dont always know what the day holds when I pick my carry pair. Sometimes I get the itch to go fishing and id rather gut fish with stainless than M4.
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I agree, I prefer a solidly HTed stainless for all culinary and sporting chores.
 
shqxk said:
Since I live in Thailand and wouldn't be able to take your challenge. I have a knife maker friend who can do 52100 or W2 against production S30V ie. Spyderco Military or some Benchmade.

I have tried this before probably 3 times along with my friend, the result is 52100 out cut Spyderco's S30V by significant margin in cutting 0.5" sisal robe.
Next time I will do a straight video when doing the same test.
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I was in your beautiful country in 1971 as a young man of 13 Y/O. My father was a teacher and we had come up from Penang Malaysia where he was teaching for a year for a vacation of sorts in Phuket for a few weeks at a Danish Marine studies institute.

I'm sure that the golden sand beaches with Coconut trees and only a few thai folks in their humble beach huts and a few oar powered fishing boats off the coast are long gone being replaced by high rise hotels with jet skis blasting back & forth and the like! I went out on the institute's dive boat with my father, brother & the local captain that knew where to take us for two of the Best Scuba dives in my life ,still to date!
Beautiful Corals and schools of brightly colored fish with all kinds of Marine life.

I hope to return someday, to Phuket and some other parts of Thailand. Friendly people, Great food and Singha Beer! :thumbup:
 
Ive become a fan of nitrogen steels, they act like carbon (even though they have little to no carbon at all) and are almost 100% stainless . Also they have goid toughness, easy of sharpening (I should say less time consuning, s110v isn't hard to sharoen, it just takes a while but some "surgical" stainless steel thats craxy soft might take no time to sharpen but its hard to put a keen ecge on, I think a lot if people use ine like the other but they're 2 different things. Also nitrogen steels take an extremely keen edge like carbon and even better if its a powder metallurgy steel like n77, the sharpest knife I ever sharpened myself, it could be gliding over my arm nit touching skin and sgaving hair like nothing, nevergot any other steel thst sharp (I do need to get me some suoer blue, I hear it takes a very keen edge.). I think steel chouce depends on what the knife is used for, what kind of knife is it and depending on the person. Fir a edc knife, sure you can do 10xx but any decent stain, ess will do so much better. For a fixed blade/bushcraft you can go either way but traditional guts will go carbon. For a chopper its carbon or any low chromium steel(cpm 3v, 4v, cpm m4, pd1, cruwear and steels in that nature)all the way. So as always, theres no"im getting a knife and what steel should I get?" or "which is better, steel a, b or c?", it all depends on use, tyoe ofknife and tge arm that will be holding thst knife, well I guess a lil brains cant hurt. Personally most if my favorite steels are stainless, nitrogen or low chromium but I do love my bk9 for chopping and their 1095 cro van is sone great stuff.
 
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