Is H1 work hardening a myth?

[Bushminer]

Skywalker wrote:

Carbon (C) 0.15 / Chromium (Cr) 14.00-16.00 / Cobalt (Co) -- / Niobium (Nb) -- / Copper (Cu) -- / Manganese (Mn) 2.00 / Molybdenum (Mo) .50-1.50 / Nickel (Ni) 6.00-8.00 / Nitrogen (N) 0.10 / Phosphorus (P) 0.04 / Silicon (Si) 3.00-4.50 / Sulphur (S) 0.03 / Tungsten (W) -- / Vanadium (V) --

Makes a bit more sense - looks like the Edge-U-Cation popup (current) in Vivaldi slips a cog on my screen.

Now to flip through through "High Nitrogen Steels" ( Gavriljuk & Hans Berns).

[me2]

It is a myth, but not in the sense that it is untrue. Like any good myth it has significant elements of truth. H1 has a composition that is close to 301, which is cold rolled to make springs. Cold rolling is a precise and controllable method of cold working/work hardening. My understanding from Sal is the H1 is received in its final shape already cold rolled and no heat treating is done after Spyderco receives it.

So, if it is precipitation hardened as well as work hardened, the heat treating is done before Spyderco gets it.

Work hardening requires deformation. Heat will possibly undo it. Most metals will work harden and austenitic metals, like 3xx series stainless steels are more responsive than usual, ie get higher hardness for the same amount of cold work. The previously mentioned 301 steel has a bonus. In addition to the usual work hardening mechanism, 301 also has a strain based martensite reaction, just as if it were quenched like a normal steel. I'm pretty sure H1 has this same martensite reaction during rolling, and that nitrogen based martensite generally harder than carbon based martensite, or that the nitrogen forms many nitrides that increase hardness more than a similar amount of carbon. I have not looked into nitrogen steels in detail.

I have seen no evidence that H1 work hardened and increased edge holding from sharpening. I have also not seen noticeable increased edge holding in serrated edges. This is based on testing and carrying of serrated and plain edge Salt 1 folders. There was a noticeable increase in edge holding after a few sharpening, but that was due to some damage in the initial edge. I rebeveled it to 12 DPS anyway. In all my years of knife nuttiness that pe Salt 1 was the only knife I did a full shave with and kept hanging the bathroom for that purpose.

[ThePeacent]

Glad to see Mr.Schemmp and Sal add to this interesting read,



and it's very nice to see experimentation won't cease: that is the method of progress and the reason of technology evolving every year.
PS: Thank you both for the awesome Rock Salt!

[zacmangray]

Reading through this thread I have formed my opinion on the topic. I do not have an H1 blade, so my opinion is purely based off what I have read.

The H1 SE blades work harden, or seem to work harden more with use then the PE. This might be because when using an SE blade there is more drag, and, grab effect on the edge causing more compression then when slicing with a PE. The extra pressure applied to each tooth increases hardness within each tooth.
SE (in my opinion) are a pain to sharpen. So the lack of sharpening the SE might have an effect over the PE. I know my PE blades get a touch up a lot more often then SE. I don't know how often you guys sharpen those SE salts?

I don't think sharpening is what work hardens the H1, I think it's the force that is applied during real world application.

Maybe the trick to getting the PE work hardened is to use the edge on everything until you can't anymore then slowly bring the edge back to where you want it. Or maybe strobe it until you have a nice convex edge Haha :D. I just need to get me an H1 blade so I can actually participate with more then just my opinion.

Thanks guys, for the knowledge you all share.

[keneke006]

This may be an old subject, but I had to create an account to answer this observation. I have an Aquasalt H1 Knife with a standard flat edge. Bummer, that as soon as I bought it, I saw that Spyderco now makes one out of LC200N. Oh well! To go on, with my AS I found it to hold an edge better after using a fine ceramic stone with a 600 or more double sided grit, Spyderco manufactured hand held stone, to obtain the edge I have now. I did feel an opposing "burr", as when sharpening other knives, to the opposite side as I was honing and as I used the stone to take the burr away on the side (work hardening via bending) then it finally obtained a rather prickly edge. Enough to cut paper almost without tearing, but not quite there yet. Maybe if I use the knife more for fishing, it will start to hold better edges? Fishing is usually summer time and seasonal depending on game sought and with the virus thingy going on, fishing pressure here in Hawaii has increased to the point that fishing has become very slow. Why? Maybe all the fish are being caught by people who go fishing to rid themselves of the boredom of staying home instead? To go on again, as long as I am by myself or with a family member then they allow it without hassle. I have not had a policeman come and tell me otherwise as of yet. So anyway, my point is, there is a work hardening happening with the burr forming on the edge and I wanted to get that out because no one has mention it in depth in the posts I have read except for one that briefly touched on it and another who reinforced the claim. IF I remember down the road some years away, I may post another one to say how my edge is doing then. Thank you for hearing me out.

[JD Spydo]

I never followed this particular thread much because I've heard so much conflicting information about H-1 steel in the past 8 years or so that it's about to drive me bats :rolleyes:

But I do hope that the OP ZENHERETIC will come to his senses and return here to Spyderville where he belongs. I miss my ol' Buddy Zenheretic. I agreed with him about 80% of the time and he was really into obscure blades like the original RONIN, Gunting and Yojimbo.

A great guy who lived in the Las Vegas area from what I remember. ZEN!!! you get yourself back to Spyderville immediately!!! That goes for you, Chad, Dr. Lecter, Doc Snubnose and about 20 others I could name. I hope ZEN is doing OK and I do hope he returns to check up on his thread at least :)

[StuntZombie]

I've used and sharpened my Wharncliffe Salt 2(serrated) quite a bit and I can't say that I've seen any evidence of work hardening. If anything, I feel like I'm starting to see reduced edge retention, and more deformation in use.

I was under the impression that the amount of friction produced during handheld sharpening would not be enough to work harden H1. Sharpening it using power equipment might be a different story.

[James Y]

This may be an old subject, but I had to create an account to answer this observation. I have an Aquasalt H1 Knife with a standard flat edge. Bummer, that as soon as I bought it, I saw that Spyderco now makes one out of LC200N. Oh well! To go on, with my AS I found it to hold an edge better after using a fine ceramic stone with a 600 or more double sided grit, Spyderco manufactured hand held stone, to obtain the edge I have now. I did feel an opposing "burr", as when sharpening other knives, to the opposite side as I was honing and as I used the stone to take the burr away on the side (work hardening via bending) then it finally obtained a rather prickly edge. Enough to cut paper almost without tearing, but not quite there yet. Maybe if I use the knife more for fishing, it will start to hold better edges? Fishing is usually summer time and seasonal depending on game sought and with the virus thingy going on, fishing pressure here in Hawaii has increased to the point that fishing has become very slow. Why? Maybe all the fish are being caught by people who go fishing to rid themselves of the boredom of staying home instead? To go on again, as long as I am by myself or with a family member then they allow it without hassle. I have not had a policeman come and tell me otherwise as of yet. So anyway, my point is, there is a work hardening happening with the burr forming on the edge and I wanted to get that out because no one has mention it in depth in the posts I have read except for one that briefly touched on it and another who reinforced the claim. IF I remember down the road some years away, I may post another one to say how my edge is doing then. Thank you for hearing me out.

keneke006,

Nice first post, and welcome to the forum!

Jim

[sal]

Aloha Keneke,

Welcome to our forum.

The answer to work hardening has not really been decided. I sharpen my H1 knives with a Sharpmaker and they get extremely sharp, plain or serrated. No burr.

FYI, We've not made the Aquasalt in LC yet.

sal

[vivi]

FYI, We've not made the Aquasalt in LC yet.

sal

Yet?

:D :D :D

[cabfrank]

Sharp vivi. See what I did there?

[Evil D]

I can't say it's a myth but I can say after doing a couple heavy reprofile jobs and lots of sharpening on two H1/SE knives I haven't seen anything that suggests that there's work hardening happening from sharpening. That detail has been debated, some say it happens and others say it's only the factory/heavier grinding that causes it.

[Bill1170]

If there were a way for us users to work harden our H-1 blades for better performance, we would be all ears for the technique. As it stands, the only clear guidance we can agree on is that H-1 in serrations performs better than H-1 in plain edge.

[Mike Blue]

....This brings up an interesting question- does forging improve a metal through work hardening? I suppose the answer should be yes, but in the context of knifemaking the next step is heat treatment so I suppose the heat treatment goes beyond the point of the forging and the end result is the same whether you start with forged steel or not.

The answer can be yes. Think a railroad rail/track. The manganese steel used work hardens from contact with heavy steel wheels holding up heavier rail cars. This area is limited to the surface of the rail plus a short distance in depth, in contact with the wheels.

There are a variety of legends/myths about edge packing that are based on the idea that finer grain along the edge of a blade can be achieved with forging. This is an observable and repeatable phenomena. Common sense would dictate that pushing the atoms of steel closer together should result in nuclear fallout. Since this is not observable around forge shops or Larrin hasn't written about it yet, it's probably not true for that part. Grains do get smaller through a falling heat with mechanical stimulus though.

[JRinFL]

I have not noticed it in any of my H1 knives. Maybe if someone were to make an axe or sledge hammer out of H1 they might see some work hardening?

[Evil D]

If there were a way for us users to work harden our H-1 blades for better performance, we would be all ears for the technique. As it stands, the only clear guidance we can agree on is that H-1 in serrations performs better than H-1 in plain edge.

I've even spoke with a couple guys who has PE knives reground hoping to see a difference but didn't.

[Albatross]

Larrin has an article about H1, and covers the work hardening topic. I shared it in another H1 thread, but I'll add it here as well, in case there are new eyes on this thread.

https://knifesteelnerds.com/2019/06/24 ... it-works/

[Wartstein]

.....

......

There are a variety of legends/myths about edge packing that are based on the idea that finer grain along the edge of a blade can be achieved with forging. This is an observable and repeatable phenomena. Common sense would dictate that pushing the atoms of steel closer together should result in nuclear fallout. Since this is not observable around forge shops or Larrin hasn't written about it yet, it's probably not true for that part. Grains do get smaller through a falling heat with mechanical stimulus though.

I really don´t know to what extent the following relates to what you´re saying, but since I am interested in ancient history, I thought I´d bring up the surprisingly hard edges of bronce age swords (so starting at about 1700 b.c.)
(I am well aware: Bronce is not steel, and H1 is not work hardened by actually hammering it!)

This vid https://youtu.be/ngjMtzJ6xgQ about the pretty famous Ewart park swords (around 800 b.c.) is really interesting and covers how they work hardened the edges by forging/hammering them.
- At around 1:45 the maker of the reproduction sword starts talking about this
- At around 2:10 he talks specifically about the work hardening of the edge
- At around 2:45 he talks about how he artifically bends and straigthens again the blade to work harden it
- From around 3:10 to 3:40 he talks again about work hardening the blade by hammering it

Then the sword gets tested pretty hard by another guy, starting at around 3:40
- From 5:15 to about 7:00 they cut through a dry birch (so pretty hard wood): The blade bends several times, which shows how soft the bronce generally is, but the edge is hard enough through work hardening to actually still somewhat cut paper afterwards
- At 08:50 the sword cuts into a wooden shield pretty well
- And from 10:40 to 11:30 one can see that bronce still can´t be a match for steel
- At 12:15 a conclusions starts

[Mike Blue]

Work hardening is no myth and bronze is a well known material for work hardening. It's fascinating to me that iron could often be a component that was used as a flux during bronze or copper smelting and that the two types of material overlapped in history. Good link Wartstein!

[spoonrobot]

I don't think work hardening of H1 is a process that can happen with non-powered hand tools.

I came to this conclusion after cutting sharpening choils in a few Pacific Salt blades. Using a regular round file cut fine and fairly quick. I've done the same with VG10, ZDP189 and S30V among others. Using a dremel stone grinding attachment at 9,000 rpm took much longer than expected (and experienced with other steels), required significantly more pressure to cut, and wore out the stone fairly quickly. It reminded me of using rotary bits on porcelain or glass.