H1 steel gaining 68HRC on the edge after heavy use?

nozh2002

nozh2002

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I read this in different forum:
"H1 steel gaining 68HRC on the edge after heavy use?"

The question is - is it true?
If it is true.
Why? How does it work?

It is sounds very easy to buy Salt with H1 then heavy use it and get in result super corrosion resistant blade with 68HRC edge! Dream of any knife-addict.

But, first is it true or not?

Thanks, Vassili.
 
I don't know about getting it up to 68 RC, but as for how it happens, H1 work-hardens, like any other steel, just that it's more pronounced in H1 for some reason, why that is, I have no clue.

An example would be bending a paperclip back and forth several times, it eventually fractures and breaks because it hardens, and instead of bending it just cracks instead.

Oh, H1 work-hardens more with SE than PE.
 
Yes it is true...unless you disbelieve Spyderco personel reporting it.

I believe it happens due to heat/friction, especially from sharpening, readjusts the Nitrogen carbon matrix into a more stabile alignment...making it harder.

PE gets to about Rc 64-65.
 
zenheretic said:
Yes it is true...unless you disbelieve Spyderco personel reporting it.

I believe it happens due to heat/friction, especially from sharpening, readjusts the Nitrogen carbon matrix into a more stabile alignment...making it harder.

PE gets to about Rc 64-65.
Click to expand...

How hard is, say, VG-10? Around Rc59-61?
 
zenheretic said:
Yes it is true...unless you disbelieve Spyderco personel reporting it.

I believe it happens due to heat/friction, especially from sharpening, readjusts the Nitrogen carbon matrix into a more stabile alignment...making it harder.

PE gets to about Rc 64-65.
Click to expand...

How was it measured? Rockwell test require flat surface as I understand.

Thanks, Vassili.
 
You will need Sal or somebody else employed at Spyderco to give the details.

All we can tell you is that it has been confirmed multiple times, straight from the horses mouth that plain edge H1 reaches mid 60s through use, and serrated edge hits the high 60s.

Perhaps you could PM Sal for some more info. I used a serrated Salt I for over a year, and I noticed significantly less sharpening as the months went by.
 
nozh2002 said:
How was it measured? Rockwell test require flat surface as I understand.

Thanks, Vassili.
Click to expand...

Vassili,
Rockwell probably is the most common ways to test hardness for hard alloys. But you need to have fairly large sample with two clean, parrallel surfaces at least .030" thick if you use A scale (for C or D scales you need thicker sample) and it's hardness around 60 HRc. In this case, probably hardness was tested on microhardness tester and converted to HRc. I remember some discussion on Spyderco forum
http://spyderco.com/forums/showthread.php?t=22168
I hope this will help, at least this confirms that this is official information.
Regards,
Roman
 
TazKristi said:
Originally Posted by TazKristi

H1 is a precipitation-hardened alloy. And yes, it is also work-hardened. Meaning that anything that you do that causes heat through friction will harden the steel further; it’s also important to note that tests have shown that it does not become brittle. The work-hardened properties of H1 have been proven by analysis independently performed by Crucible Specialty Metals. It is this that explains why an H1 blade with a SpyderEdge has better edge retention than it's PlainEdge counterpart. In the end, the analysis from Crucible found the Rc at the spine was 58, however at the edge it had increased in both the PlainEdge (to 65 Rc) and the SpyderEdge (to 68 Rc).

The Salt Series knives are being made and promoted to a market where corrosion resistance is important.

So, is H1 possibly just another flavor-of-the-month? Possibly, but hype can only go so far.

Kristi
Click to expand...

It will be easy to test, I think.

I think Spyderco need to do some "heat through friction" as part of their production - kind of advanced HT and stop doing all other steels! Again can you imagine -

"Who wants super corrosionn resistant Military with tough blade and 65HRC edge?"

Do anybody have any suggestion how to make my edge 65HRC - what kind of material I should use ad for how long?

Thanks, Vassili.
 
sherlockbonez said:
Gonna pick up a salt now..thanks for spending my money for me guys...
Click to expand...

Well, I myself does not really buying this yet, it sounds too good. I hope Sal will make it clear. H1 was used first by Spyderco 2003 first and in that thread they Sal sad that edge retention is not as good as top rated steel that time:

Sal Glesser said:
Hi Jeffrey. H-1 comes hard from the foundry. Harder to work it. Drilling, reaming, etc.

We couldn't get Rc60. Even 58 is tough at this time but achievable. Benchmade's piece Rc'd at 58.15 average.

Our Delica uses H-1 for lock and blade. other corrosion reistant materials (including 17.7 for other parts.

H-1 is a fairly new steel and still has much remaining to learn. We're not going to run out and make everything in H-1. Edge retention, in our tresting was not as good as 440C, ATS-34 or VG-10 in plain edges. Serrations were very good.

sal
Click to expand...

So I am wondering what Sal may say today and of coures about this "friction heat treatment" to rize hardness to 65HRC.

Thanks, Vassili.
 
nozh2002 said:
So I am wondering what Sal may say today and of coures about this "friction heat treatment" to rize hardness to 65HRC.

Thanks, Vassili.
Click to expand...
My guess is that he would agree with what his employee Tazkristi said in your previous quote, which was a few years after Sal's post....:D
 
I find this hard to believe....does it mean that H1 will hold its edge longer with wear as the hardness goes up (which co-relates with edge holding)??

wouldn't this make the H1 Pacific / Salt / Tasman a self-sharpening knife?
 
spyken said:
I find this hard to believe....does it mean that H1 will hold its edge longer with wear as the hardness goes up (which co-relates with edge holding)??

wouldn't this make the H1 Pacific / Salt / Tasman a self-sharpening knife?
Click to expand...

Even it is true, it does not make then selfsharpening, but selfhardening instead.

I heart about steel aging, like austenit steel loose quality in time because austenit turns into something else. I heart about increasing hardness by cryo treatment - to turn austenit to cementit (if I got it right), so I keep sme of my bulat knives from Kirpichev in freezer for long time. But it is first time I heart about this friction hardening.

Thanks, Vassili.
 
spyken said:
I find this hard to believe....does it mean that H1 will hold its edge longer with wear as the hardness goes up (which co-relates with edge holding)??

wouldn't this make the H1 Pacific / Salt / Tasman a self-sharpening knife?
Click to expand...
It is important to realize that thanks to modern chemistry/technology they are able to make compounds that were not previously possible (like forcing Nitrogen into the iron matrix). Such advances are going to yield results differing from previously expected results.

It is also worth considering that H-1 is a Japanese steel and per Spyderco in the above quotes, it was tested by an American competitor (CSM). Personally, I would think if a competitor was going to falsify results of their tests on a competitors steel they wouldn't make them so impressive. :D
 
zenheretic said:
I believe it happens due to heat/friction, especially from sharpening, readjusts the Nitrogen carbon matrix into a more stabile alignment...making it harder.

PE gets to about Rc 64-65.
Click to expand...

IIRC Sal stated several times that H-1 is work hardening steel. Work hardening is also known as cold forming.

Common examples of this method are old scythes you had to hammer to maintain the edge. Well known is also processing of e.g. bronze when by cold forming you can harden the edge of otherwise non heat treatable material.

However effects of cold forming may be removed by annealing the material - which is done by heat.

Ergo it is quite confusing for me - if H-1 is work hardening steel these (65+HRC) results cannot be achieved by heat (also please note that grinding is not cold forming!).
 
By "Friction heat treatment" do you mean "work hardened"? Work hardened is the term that was used to describe the process. There's no point in making up new terms when there is already an accepted name for the process described. Joe
 
Well since I sold and gave away all my other spydies besides my manix, I'm gonna pick up a yellow SE Salt anyways to see how well it works.
 
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