Don't Be a Sucker for getting hung up about blade steels!
You know THE most important thing about about knife steel is that it will do the job for you. Currently there is a paradox of choice when it comes to which blade steel. Raw material manufacturers will have you believing whatever but in most cases the top customers ("Bread and Butter" customers) for these manufacturers are NOT knife manufacturers but people in the business of Tooling and other industries. Now read those above lines again before getting on your high horse, I said "top customers" I didn't say "Only customers".
Next you have knife manufacturers all vying for pole position of their products. Re invention of all the classic blade designs: Drop points; spear points, Western Tantos'; Bowies' etc etc have been done to death. Why we re market old products under "new" fancy names like G10! Simply because it has a funky kind of scientific high tech sound to it. No one mentions this stuff has been around for donkeys years! Handles, well we see countless designs and materials being used; from synthetic to natural. I mean how many times can we reinvent the bicycle?
What has been lacking is a thorough pursuit of ergonomics in handle design, with only few manufacturers emphasising this all forgotten over blade design aspects.
THERE IS NO SUPER STEEL!
No, sorry to disappoint you there isn't. If there was there would be a clear market leader in the supply of raw materials and there isn't as yet. The reason is simple. It depends on the environment the knife is getting used in, will dictate what is the "best" alloy of choice for production and intended purpose.
I'm not sure how old you are, but I can remember very plainly when 440C was the "super steel" for knives, so much so that countless "el cheapo" knives were being labeled as such and certainly weren't made with 440C. Then came ATS34, BTW these two alloys contrary to ALL marketing hype, are still very good knife steels. Their "goodness" didn't change. The fact is, industry marketing fuelled by ill informed social media pundits, introduced new terms to trick the unwary like:
"Chipping"
"Folding"
"Rolling edges"
I'll put these terms into perspective now.
All knife edges will either "chip" or "roll" if they undergo enough force against a harder object or an immovable object.
Anyone who tries to tell you otherwise failed physics or simply didn't do it (ok I'll excuse you if you didn't do it but not excuse you for blindly believing the market hype).
P=F/A That's pressure equals Force divided by Area.
Since the area of the actual knife edge is very very small, any significant force will produce a huge pressure on the blade edge.
Correct heat treatment regimes are paramount to achieve the same specifications that raw material manufacturers state.
Correct heat treatment costs serious money on an industrial scale. It is a science and an art but firstly a science. Just look at the making of a Katana. I've watched them being made in front of me whilst living in Japan. Nothing is done by chance or "bucket chemistry".
Certain knife alloys are marketed towards gullible (no offence intended but most manufacturers of raw stock will list all of their Technical PDF's in the public domain- much can be learnt from them even if you aren't a metallurgist or the like) end users by referring to qualities that will only ever be apparent if used to make milling tools, not knives. Milling tools are subject to repeated and repeatable forces. Knives are not. Knives are controlled by our hands and everyone's hands are different and everyone will apply forces/use the same knife in a different manner in any test (biological/mechanical variation). This is a non repeatable process. There will be much variation involved here. It is for this latter point that attempting to judge how good a steel choice is for knives based solely on non scientific tests is pretty meaningless as it simply boils done to someones' opinion. That's OK but it is exactly that opinion UNLESS.......Even when the someone ( the same someone) does many tests. UNLESS that someone uses the correct statistics to analyse their results. Otherwise it's just an opinion. (I'm wearing my scientist hat now- sorry).
Once the raw product leaves the factory, no guarantees are given about the resulting knife steel as this is beyond their control. I've had problems with "high end" steel alloys and the manufacturer simply said it's the issue of the knife manufacturer- AND they were right.
The importance of Surface treatment of Stainless Alloys.
A/ Mirror Polished
B/ Polished
C/ Milled smooth (but milling marks present to naked eye)
D/ bead blasted/shot blasted/stone washed
E/ PVD (Physical Vapour Deposition- sometimes called Sputtering)-(including amorphous diamond- like carbon (DLC), nitriding, TiN etc etc.
F/ Teflon over milled
G/ Mil Spec blacking/chemical blacking/bluing/ etc.
For any given stainless alloy to have maximum resistance to corrosion then the type of surface finish is important.
According to my correspondence with technical staff of a large European steel producer, other than soluble Chromium, i.e. Cr not bound up as carbides, the final surface finish is critical to achieve the optimum resistance to corrosive forces all things being equal.
Point "A" is best
PVD will confer better resistance to corrosion over a basic milled surface alone.
Teflon is ok but is will wear out. It is cheaper to apply than a PVD process.
Stone washed is not going to be as effective as a super smooth surface at resisting corrosion for identical alloys.
"D" will not confer any added corrosion resistance to the alloy.
The carbon content
Guess what, it's not necessary to have any carbon these days in knife steel alloys LOL. There are other very hard components such as nitrides. Ok these alloys are not mainstream as yet.
Certain alloy's properties are more important to the knife manufacturer than the end user.
More to come!