Tell Me your thoughts on CPM 15v

[DeadboxHero]

I'd like to here people's thoughts CPM 15v steel for thin fixed knives for 4" blade for hunting and general use.

Shawn.

 

[NJBillK]

My thought is that I would like to try it, so I can make an informed decision.

The truth of the matter is that the alloy is used so infrequently, that you are going to have very little folks to weigh in, that have in hand experience with the alloy.

You might want to try and reach out to Michael Christy on YouTube. He is a nut when it comes to different alloys, and I would be willing to be that he either has a custom in the alloy already, or has one in the works.

Edit to add:
Gary may have worked with it. So he might be able to chime in.
@gscreely

 

[19-3ben]

Well..

CPM3v x 5 = CPM15v

Do I have to show my work?

P.S.- I have nothing useful to add. I never even heard of 15v until reading this thread. My guess is to see if you can get an answer out of Big Chris. He's pretty solid on the exotic CPM stuff...

 

[Twindog]

I've seen people use it, but it never seems to catch on.

My sense is that 15V lacks too much toughness. According to Crucible, it's about half as tough as 10V. You get a lot more wear resistance, but 10V is at the bottom of what I consider useful for a knife. I found it easy to break the 10V K2 from Spyderco.

 

[chumaman]

new heat treatment gives a lot better results
but in my opinion it is still too thick knife 0,55mm=.021inch behind edge
still a very respectable knife and steel
and this proves HT to be a very important item

 

[DeadboxHero]

I've seen people use it, but it never seems to catch on.

My sense is that 15V lacks too much toughness. According to Crucible, it's about half as tough as 10V. You get a lot more wear resistance, but 10V is at the bottom of what I consider useful for a knife. I found it easy to break the 10V K2 from Spyderco.

Dang what broke the k2?

 

[Natlek]

new heat treatment gives a lot better results
but in my opinion it is still too thick knife 0,55mm=.021inch behind edge
still a very respectable knife and steel
and this proves HT to be a very important item

Well , for me it proves only that he missed HT on first knife ! Come on , it is impossible to make such a difference with two different HT proces on same steel .............even if it was forged personally by Hephaestus !! 1350/2950 ??????

 

[shinyedges]

Well , for me it proves only that he missed HT on first knife ! Come on , it is impossible to make such a difference with two different HT proces on same steel .............even if it was forged personally by Hephaestus !! 1350/2950 ??????

This is incorrect. Heat treat is make or break. Literally.

 

[chumaman]

Well , for me it proves only that he missed HT on first knife ! Come on , it is impossible to make such a difference with two different HT proces on same steel .............even if it was forged personally by Hephaestus !! 1350/2950 ??????

are both the same hardness?/ 63HRC therefore only in the HT procedure
edge stability etc. etc.

 

[Natlek]

This is incorrect. Heat treat is make or break. Literally.

Are you sure about that ? Do you have same example to show me ? 1350 vs 2950 cut ???????????

 

[shinyedges]

Are you sure about that ? Do you have same example to show me ? 1350 vs 2950 cut ???????????

Put as many question marks as you like. Heat treat any steel correctly and then don't heat treat the same steel or incorrectly heat treat it and the difference is night and day.

A botched heat treat could mean anything, it could mean the knife was heated to the point of being annealed, it could mean it got tempered for 1 minute... we don't know.

The difference between a well executed heat treat protocol and a potential annealed blade is silly.

 

[Twindog]

Dang what broke the k2?

Well, I didn't like the knife. I didn't like the blade geometry. I thought the construction was too flimsy. And I wondered if that thin of a blade in 10V had much toughness. So I applied lateral hand pressure on the blade (holding the handle, tip on the desk) and an inch broke off the end. I wasn't trying to break it; I was testing it with pressure that I though it should be able to handle. Yes, this was abuse. No, I don't normally use a knife like that. No, the damage didn't sharpen right out.

But that test, with just hand pressure, showed me that the steel lacked too much toughness. I gravitated to K390, which is close to 10V in wear resistance, but has more toughness. I do have a Phil Wilson Bow River in 10V at 63 or 64 Rc that has extremely acute geometry. I baby that knife.

 

[Natlek]

Put as many question marks as you like. Heat treat any steel correctly and then don't heat treat the same steel or incorrectly heat treat it and the difference is night and day.

Are you kidding me ? What is then incorrect in my post ? So do you have same example of your claim ? 1350 vs 2950 cut ? Relevant one .Not on tube , on tube rust even most stainless steel

Well , for me it proves only that he missed HT on first knife ! Come on , it is impossible to make such a difference with two different HT proces on same steel

 

[DeadboxHero]

Well, I didn't like the knife. I didn't like the blade geometry. I thought the construction was too flimsy. And I wondered if that thin of a blade in 10V had much toughness. So I applied lateral hand pressure on the blade (holding the handle, tip on the desk) and an inch broke off the end. I wasn't trying to break it; I was testing it with pressure that I though it should be able to handle. Yes, this was abuse. No, I don't normally use a knife like that. No, the damage didn't sharpen right out.

But that test, with just hand pressure, showed me that the steel lacked too much toughness. I gravitated to K390, which is close to 10V in wear resistance, but has more toughness. I do have a Phil Wilson Bow River in 10V at 63 or 64 Rc that has extremely acute geometry. I baby that knife.

That's crazy man. How much tougher do you think k390 is? I've read the spec sheets and I own a police 4 but I haven't tested the toughness of it.

 

[NJBillK]

Just because both knives were 63hrc, doesn't mean they are equal.

To expand upon Shinyedges comment; if you took two blanks, and treated them nearly the same:
1) thermal cycled 3x, then went through the HT regimen correctly.
2) Overheated without thermal cycling, then went through the HT regimen (post thermal cycle portion).

Both blades 1 and 2 would be able to hit near max hardness, but blade #2 would perform to a much lesser standard than blade #1. This would be evident in edge retention and toughness. The difference in performance would be due to the grain growth that was allowed to propagate in #2, vs it being kept in check and minimized in blade #1.

Hardness doesn't mean a thing, other than give you one bit of information needed to piece together a puzzle...



Edited for incorrect numbering.
Also, I think you both are basically saying this. That HT is more than an HRC value.

 

[shinyedges]

Are you kidding me ? What is then incorrect in my post ? So do you have same example of your claim ? 1350 vs 2950 cut ? Relevant one .Not on tube , on tube rust even most stainless steel

Whoops it's been a long crappy day at work, carry on.

Also, I don't know what you are trying to convey, once again.

 

[Natlek]

I say no one on this world can HT ANY steel to get 130 % better blade then HT protocol given by manufacturer..................

 

[Korean Hog]

I've read through tons of heat treating information, however I've never heat treated steel myself. Heat treating to me seems like the kind of thing you've got to do hands on to really speak in depth about which heat treating protocol is going to be the best for a given alloy.
Granted, understanding the process and science behind heat treating can tip you off as to what a manufacturer/ maker may have done right or wrong and/or which maker has the best heat treat for a given steel.
I tend to think of heat treating as breathing life into the steel; shaping makes a body, but heat treating makes that knife a knife, otherwise it's just knife shaped metal.

Did a quick search on cpm 15v and the chemical comp looks crazy!
From Crucible data sheet:
Carbon 3.40% Chromium 5.25% Vanadium 14.50% Molybdenum 1.30%
CPM 15V is intended for applications requiring exceptional wear resistance. It has more vanadium carbides in its microstructure than CPM 10V and provides more wear resistance and longer tool life in those applications where 10V has proven to be successful. CPM 15V also offers an alternative to solid carbide where carbide fails by fracture or where intricate tool design makes carbide difficult or risky to fabricate.
With its nearly 15% vanadium content, CPM 15V has the highest wear resistance of any cold work tool steel available today.

Can't speak to the quality of a blade made from 15v, never even heard of one, but I bet the edge retention would be out of this world! If heat treated properly...

 

[Twindog]

That's crazy man. How much tougher do you think k390 is? I've read the spec sheets and I own a police 4 but I haven't tested the toughness of it.

From looking at the Bohler site, K390 has just a touch less wear resistance than 10V, but about 22 percent more toughness. K390 is a third generation powder steel, so it's grain structure will be small than 10V's and it will be cleaner. But both are A11 class steels.

I've never tested K390 for toughness because the knives I have in that steel are ones I like a lot. And the problem with toughness testing is that it's destructive.

You might want to check out this Bohler site. It compares in various charts K390 to 10V and 15V. 15V will lose a lot of toughness.
http://www.bohlernn.ru/files/K390DE_MICROCLEAN.pdf

I think K390 is right in the sweet spot for highly wear-resistant steels that are reasonably tough.

 

[TheEdge01]

I’ve been leary about trying ZDP-189 due to low toughness which means it is prone to chipping or snapping. Well, CPM15V is yet another one I will avoid as well.