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Zdp-189

I would be very interested to see what kind of toughness laminated ZDP could achieve, though I agree with Quite Storm. You would like a nicely soft and ductile steel for the surrounding layers for maximum dampening and shock absorption. Maybe even something of the 300 series. But there might be problems with the hardening of the ZDP core. I don't know.

I would love to see something like Dozier's Slim Outdoorsman or Krein's TK-3 in ZDP-189.
 
Use 420 and heat treat it as if it was pure ZDP-189, you would end up with sides from 45/55 HRC depending on what version of 420 was used. This of course does nothing for the behavior of the edge, it just keeps the blade from cracking under heavy impacts and it will take a set rather than break if overstressed laterally.

-Cliff
 
Deadhead Archer said:
Imagine ZDP-189 sandwiched between 154CM....or another high-end stainless...

drooooools......
Click to expand...

They allready make a ATS-34 with ZDP core, I love it!!!
 
Unless I'm missing something here, ATS/ZDP/ATS is definitely inferior to 420/ZDP/420 in every way.
 
Both are made by Hitachi, you can buy both as bar stock. I assume that the reason for using ATS-34 as outer layers instead of 420J lies in the heattreat. I have read that laminated blades are require some thought during heat treat because the outer layers may slow the cooling rate during quenching and may have different expansion and contraction rates than the core which would result in stress induced between the layers, but I know nothing further, but the fact that many of the Caly Jr. blades had a small permanent set indicates, that this isn't that easy. Aside from that I am with Quite Storm: I see only disadvantages in using ATS-34. Lower corrosion resistance, lower toughness, higher price.
 
Quiet Storm said:
Unless I'm missing something here, ATS/ZDP/ATS is definitely inferior to 420/ZDP/420 in every way.
Click to expand...

ATS as the outer laminate is more scratch resistant and stronger, it is pretty easy to bend laminates with really soft sides. Plus ATS-34 is generally thought of as a "better" steel and perception can't be trivially ignored in favor of performance if you are actually trying to sell knives. HoB makes an interesting point, steels do have different changes in dimension during hardening though this would seem to be more of an issue if it was just a single ply laminate than triple.

-Cliff
 
In a laminated blade, I guess you want a hardness of, say, 54-56 HRC for the outer layers, regardless of the steel used. Anything higher than that largely defeats the very purpose. 54-56 is where 420J2 is at its optimum and ATS is not. Is ATS really stronger and more resistant to scratches than 420 at hardness levels in the mid-50s?
Besides, if you want to avoid scratches, you should go for a regular steel, not a laminate. If you're looking for a really good compromise between toughness and edge-holding, laminated steel may be for you. 420 is tough as nails and ZDP holds an edge extremely well.

But yes, it's sound marketing, as evidenced by the positive reception of such a laminate in this thread.
 
To clearify, not opposing your viewpoint, I would pick 420/ZDP as well, however not everyone buys knives because of how they actually work.

Quiet Storm said:
Is ATS really stronger and more resistant to scratches than 420 at hardness levels in the mid-50s?
Click to expand...

ATS-34 and ZDP have very similar hardening cycles, what leaves ZDP at 67/68 HRC would not produce ATS-34 at 55 HRC, see :

http://translate.google.com/transla...firefox-a&rls=org.mozilla:en-US:official&sa=G

and

http://www.crucibleservice.com/datash/ACF13AF.pdf?CFID=363391&CFTOKEN=10017289

Besides, if you want to avoid scratches, you should go for a regular steel, not a laminate.
Click to expand...

And not use the knife.

-Cliff
 
I did check the charts, but I'm not sure how I can compare the HT temperatures in the 154CM pdf to the graphs in the first link...the remaining Japanese doesn't help or maybe I just didn't look hard enough. Hardening ZDP and ATS/154CM together, with the primary focus being ZDP's performance, would leave the other steel at what hardness?
 
robertmegar said:
Here is some comparison info from Hitachi:


ZDP-189CharpyU-notchtest.JPG
Click to expand...

But Rockstead for example recommends to HT it to 65HC.

This diagram will lookdifferent if you have ZDP-189 at 65 HRC and ATS-34 at 63HRC

Thanks, Vassili.
 
I have heat treated the ATS-34 laminate at work. I shot for 67 HRC in the ZDP core, and the ATS-34 had a reading of 58-59 HRC. I will post some pictures of the knives I made when I get back to work on monday.

I agree that marketing probably had a lot to do with the use of ATS-34 being use in the laminate, and heat treat compatability the other.

Besides performance, the other reason I like this laminate is asthetics. I hand rubbed the blades to a 1000 grit finish and did a very light etch in ferric chloride, resulting in a dark core while the ATS-34 was unafected.
 
Just compare similar runs, for example soaks at 1025 on ZDP-189 and 1900 F on ATS-34 and tempers at 200 C give a core of 67 and sides of 60 HRC. Note the soak temperatures of ZDP-189 are fairly low, which is opposite to the high vanadium CPM stainless steels which can be problematic for knifemakers. I would like to see torsional toughness/strength curves for ZDP-189, and wear resistance comparing the high/low tempers.

-Cliff
 
Tim Galyean said:
I have heat treated the ATS-34 laminate at work. I shot for 67 HRC in the ZDP core, and the ATS-34 had a reading of 58-59 HRC.
Click to expand...

The hardness levels you and Cliff describe for ATS/154CM are pretty much what I expected. So what you got there is essentially a blade with ZDP's edge-holding and ATS-34's toughness. The latter doesn't exactly sound bad, but not as good as 420 layers either.

By the way, I visited your website earlier tonight and I have to say that you make some awesome knives, great designs. Your good work definitely deserves more recognition. Keep it up!
 
Tim's work? Unbelievable, truly amazing I think. As far as recognition, try finding and affording one of his pieces.....

Back to ZDP.... why would you NOT want to HT it up to 67.5 Rc?!??!? You would be better off with other steel then.
 
I didn't know that his knives are already popular - to be honest, I don't think I've heard his name before. That said, judging from the pictures on his site it doesn't surprise me at all that his knives are in high demand.

Who said that I wouldn't want to have ZDP HTed to the best of its potential?
 
robertmegar said:
Back to ZDP.... why would you NOT want to HT it up to 67.5 Rc?
Click to expand...

Because the materials data might suggest a better alternative, O1 for example has toughness/strength peaks just below its maximum hardness, so it works better for some applications drawn to 63.5 HRC vs full hard. The materials data for ZDP-189 simply isn't available to make such a decision. Phil has started working with it now, hopefully in awhile he will be able to make some comments on the abilities of the steel over a range of heat treatments. I would not be too concerned about the impact toughness, for a steel of this type it doesn't matter significantly anyway.

-Cliff
 
Sorry to digress, but man, that Junk Yard Dawg Viva LasVegas is absolutely stunning :eek: .
 
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