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

I've owned 2 PE Salt I's and both of them did get harder at the edge after some heavy use and sharpening.

I've had to do hardness tests on various metals with a UCI-type harness tester and work hardening is a fairly relevant issue on a lot of metals. The prep (including grinding) required to actually do the test can harden the surface and skew the results. Anyway, in a knife steel, work hardening can be your friend. :D :thumbup:


ETA: Forgot to mention I didn't try to check the actual hardness of my blades, but it was an OBVIOUS performance increase. I was using them to cut a lot of cardboard and insulation on a daily basis, so as they got harder, it was very plain that the edge was lasting quite a bit longer.
 
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.
Click to expand...

The higher carbon steels have retained cemetite, but the cryo treatment allows the final conversion of austenite to martensite. Martensite is hard, giving greater wear resistance, and a higher rockwell, although only slightly. The cold finish degree depends on the steel's composition, the quench, and any tempering that may have been done. The effective temperatures can be as high as freezing, and as low as -200 or colder. keeping the knives in the freezer for a long period of time doesn't help, a day should be fine, and once the martensite forms, there is no need to repeat the treatment, unless it gets really cold outside. I have contemplated doing a home cryo with dry ice on some race car components, to increase lifetime and durability.

later
xdshooter
 
xdshooter said:
The higher carbon steels have retained cemetite, but the cryo treatment allows the final conversion of austenite to martensite. Martensite is hard, giving greater wear resistance, and a higher rockwell, although only slightly. The cold finish degree depends on the steel's composition, the quench, and any tempering that may have been done. The effective temperatures can be as high as freezing, and as low as -200 or colder. keeping the knives in the freezer for a long period of time doesn't help, a day should be fine, and once the martensite forms, there is no need to repeat the treatment, unless it gets really cold outside. I have contemplated doing a home cryo with dry ice on some race car components, to increase lifetime and durability.

later
xdshooter
Click to expand...

I am not sure why but it defenetely get little better in freezer. Again this is bulat not steel, so nobody really knows what is going on in it.

knife-83-015.jpg


Thanks, Vassili.
 
Vassili, I've been wanting to get some Bulat / Wootz blanks...where can I get them for a project I want to do?
 
Spyderco was NOT the first commercial production knife company to use H-1. Back in 02 I bought a Benchmade fixed blade dive knife made with H-1 before I ever even heard of the Spyderco SALT series. I had that knife for a long time before I traded it in 05. It was used in the Benchmade model 100S-H20 which came in either a black or a yellow handle.

I think BM still makes that knife but they no longer make it with an H-1 blade. They now use X-15TN stainless on those. Now BM never made any claims about work hardened H-1 getting a harder edge every time you sharpened it that I can remember and I read a lot about that knife before I bought one. And I don't know if all H-1 is created equal but I do distinctly remember that the first runs of that BM dive knife of theirs was introduced in either late 01 or early 02 which was way before I ever heard of the SALT series and the first ones did indeed have an H-1 blade. I have an older Tactical Knives magazine with a big article about that knife to prove it.
 
JD Spydo said:
Spyderco was NOT the first commercial production knife company to use H-1. Back in 02 I bought a Benchmade fixed blade dive knife made with H-1 before I ever even heard of the Spyderco SALT series. I had that knife for a long time before I traded it in 05. It was used in the Benchmade model 100S-H20 which came in either a black or a yellow handle.

I think BM still makes that knife but they no longer make it with an H-1 blade. They now use X-15TN stainless on those. Now BM never made any claims about work hardened H-1 getting a harder edge every time you sharpened it that I can remember and I read a lot about that knife before I bought one. And I don't know if all H-1 is created equal but I do distinctly remember that the first runs of that BM dive knife of theirs was introduced in either late 01 or early 02 which was way before I ever heard of the SALT series and the first ones did indeed have an H-1 blade. I have an older Tactical Knives magazine with a big article about that knife to prove it.
Click to expand...

And nobody question that BM used it first. Sal himself get them credit for this as I remember.

I just like to hear official Spyderco support for this claim.

Thanks, Vassili.
 
This are the pictures of my new Pacific Salt:

Spyderco-Pacific-Salt-001.jpg


Spyderco-Pacific-Salt-004.jpg


Spyderco-Pacific-Salt-002.jpg


Spyderco-Pacific-Salt-003.jpg


Still looking forward for some word from Spyderco on this selfhardening claim...

Thanks, Vassili.
 
Hi Vassili,

Crucible did do micro hardness testing on the Salts and determined that the blades were in fact work hardened in the grinding processes and was 65 at the edge of the plain edge model and harder at the edge of the serrated edge model.

sal
 
Sal Glesser said:
Hi Vassili,

Crucible did do micro hardness testing on the Salts and determined that the blades were in fact work hardened in the grinding processes and was 65 at the edge of the plain edge model and harder at the edge of the serrated edge model.

sal
Click to expand...

Thanks Sal,

This is not a hype! Cool. Are there any numbers any practical recommendations? I use a lot of friction while sharpening and polishing the blade on leather I am wondering will it be enough... Is it heat from friction or mechanical pressure? Why don't you put attitional friction on edge as part of manufacturing process?

Thanks, Vassili.
 
Now all we need is some skelotonised titanium liners and a wave and we'd have the most durable and EDC friendly knife ever.
 
nozh2002 said:
Thanks Sal,

This is not a hype! Cool. Are there any numbers any practical recommendations? I use a lot of friction while sharpening and polishing the blade on leather I am wondering will it be enough... Is it heat from friction or mechanical pressure? Why don't you put attitional friction on edge as part of manufacturing process?

Thanks, Vassili.
Click to expand...

Hi Vassili,

I personally cannot say that a non mechanical use will make the blade harder. We have no evidence to support that. We have had a few customers say thet they believe it to be true, based on their personal expericences.

As far as what ae can and cannot do, we're still learning about this interesting new material.

sal
 
I think I need a yellow handled spyderco soon....Sal, how about a run in orange.....
 
You must log in or register to reply here.
Back
Top