Powdered VG10?

[Bdubs808]

I'm curious, is there a steel that is powdered VG10? If there is, I think that would be a cool choice for the next round of "Seki Standards" (LB, MB, DF2, D4, Stretch, E4).

[bearfacedkiller]

I do not know if there is a powdered VG10 but I think that CPM154/RWL34 would have you in the ball park as far as performance goes. I am curious what others think would be close.

http://www.zknives.com/knives/steels/st ... hrn=1&gm=0

[Eli Chaps]

I'm curious what the perceived benefit would be? Not being sarcastic, legitimately asking.

What would the PM process in the same alloy bring to the table that would set it apart from the cast material? Finer grain size? It's already pretty tough so not sure there's ductility benefits but maybe.

[StuntZombie]

I think VG-10 is already so uniform and fine grained that not much would change with a powdered version.

[Bdubs808]

Thanks for the input. It seems to be a case of "if it ain't broke, don't fix it", huh? I would buy that steel anyway if it were ever available :D

[Bill1170]

I think VG-10 is already so uniform and fine grained that not much would change with a powdered version.

This is my impression as well.

[bluntcut]

One of the key benefit from PM process is creation of fairly consistence primary carbide size ~1.5+um. Vs ingot carbide of mixed-sizes 10+um to sub micron. Just eyeball micrograph of cpm154(PM vg-10 should be similar) vs vg-10/ats-34, easy to spot ingot steel has much more carbide count/number than PM counter part. Which one is better - not sure because that depend on tasks but I suspect in a double blind test for variety of tasks - I think, it would be inconclusive. Hence bad ROI to PM certain steels.
btw - ht controls (mostly) grain diameter of aust/mart matrix. For some steels PM process can help some.

[Bdubs808]

Just read the December Spyderco Byte and I realized that they did the thing I was asking about by designing SPY27:
"Continuing this evolutionary path, the new Manix 2 Lightweight proudly features our proprietary CPM SPY27 blade steel. Starting with a tried-and-true Spyderco standard—Japanese VG-10 stainless steel—our goal was to enhance its alloy composition with the addition of nitrogen, niobium, and additional carbon and vanadium, and then produce the steel with the benefits of the particle metallurgy process. Working in close cooperation with Crucible Industries for more than a year of research and development, we were able to do exactly that."

[Larrin]

VG-10 does not have a carbide structure as fine as powder metallurgy products. I agree that CPM-154 would be in roughly the same property range.

[Bolster]

Just read the December Spyderco Byte and I realized that they did the thing I was asking about by designing SPY27:
"Continuing this evolutionary path, the new Manix 2 Lightweight proudly features our proprietary CPM SPY27 blade steel. Starting with a tried-and-true Spyderco standard—Japanese VG-10 stainless steel—our goal was to enhance its alloy composition with the addition of nitrogen, niobium, and additional carbon and vanadium, and then produce the steel with the benefits of the particle metallurgy process. Working in close cooperation with Crucible Industries for more than a year of research and development, we were able to do exactly that."

Correct...from Spyderco's perspective, SPY27 is an upgraded PM version of VG-10.

What would the PM process in the same alloy bring to the table that would set it apart from the cast material? Finer grain size? It's already pretty tough so not sure there's ductility benefits but maybe.

Have a look at comparisons between ATS-34 and the powdered version RWL-34; or between 154-CM and the powdered version CPM-154. Smaller more uniform carbides, thus a tougher steel able to hold more acute angles.

[The Mastiff]

People are funny about changes to their pet steel. Recall when Powdered D2/CPM D2 was released there was a certain amount of people who didn't like it claiming it didn't have the "bite" of regular ingot D2. No question the powder process did it's thing with D2 and it was less chippy at the higher hardness with thin edges from my recollection. I like CPM D2 myself but there again I liked ingot D2 for a long time even before it became so popular. My first home made knife was D2.

[Bolster]

Recall when Powdered D2/CPM D2 was released there was a certain amount of people who didn't like it claiming it didn't have the "bite" of regular ingot D2.

That's interesting. Do you think there's anything to it? With ingot D2's huge carbides, if you rip them out during sharpening, do you get more of a sawtooth edge that, when fresh off the sharpener, seems more toothy? (Edge would obviously degrade rather quickly in comparison to the PM version, I'd guess...)

[The Mastiff]

That's interesting. Do you think there's anything to it? With ingot D2's huge carbides, if you rip them out during sharpening, do you get more of a sawtooth edge that, when fresh off the sharpener, seems more toothy? (Edge would obviously degrade rather quickly in comparison to the PM version, I'd guess...)

There is something to it, yes IMO. The carbides and bite are things D2 is known for when it comes to edges. Can everybody tell or care? Likely not but I believe some could because I was one of them. I can tell D2 and 440C by sound and feel when sharpening. On my coarse stones it sounds like I am sharpening sandpaper or something. It makes an unusual sound like that which I don't get with even very high carbide steels using vanadium or tungsten type carbides. Those large chrome carbides have their own sound and feel.

I also say the carbides are cut not just pulled out. On my diamond stones anyways. It still is a 'sawtooth" edge if you magnify it enough and with D2 that made it very popular on hunting and skinning type knives when it came to boars and large elks and moose. The fur gets matted and has lots of dirt and grit in it and the D2 knives as made by Bob Dozier became popular with hunters and guides back in the day before steels with vanadium like 10V became more popular and well known.

Joe

[skeeg11]

That's interesting. Do you think there's anything to it? With ingot D2's huge carbides, if you rip them out during sharpening, do you get more of a sawtooth edge that, when fresh off the sharpener, seems more toothy? (Edge would obviously degrade rather quickly in comparison to the PM version, I'd guess...)

There is something to it, yes IMO. The carbides and bite are things D2 is known for when it comes to edges. Can everybody tell or care? Likely not but I believe some could because I was one of them. I can tell D2 and 440C by sound and feel when sharpening. On my coarse stones it sounds like I am sharpening sandpaper or something. It makes an unusual sound like that which I don't get with even very high carbide steels using vanadium or tungsten type carbides. Those large chrome carbides have their own sound and feel.

I also say the carbides are cut not just pulled out. On my diamond stones anyways. It still is a 'sawtooth" edge if you magnify it enough and with D2 that made it very popular on hunting and skinning type knives when it came to boars and large elks and moose. The fur gets matted and has lots of dirt and grit in it and the D2 knives as made by Bob Dozier became popular with hunters and guides back in the day before steels with vanadium like 10V became more popular and well known.

Joe

Gosh that brings back memories when Dozier was one of the few who consistently got D2 heat treat right. Still have a filet and a couple of his skinners. Back in the day, that toothy bite off of DMT stones was a revelation. Processed my share of deer & wild pig with 'em. Now-a-days I'm likely to be carrying a Spyderco SpydieChef for that purpose.

[The Mastiff]

Back in the day, that toothy bite off of DMT stones was a revelation.

That is the truth. After making a couple of knives it dawned on me how much knowledge and work it took to make the knives so consistently excellent. When they got new batches of steel they had to test and fine tune the heat treat to get everything correct. Having the hardness come out where you want it is only part of that story. Grain size, carbide size and retained austenite all have to be similar to make the knives perform the same batch to batch. That sort of quality doesn't happen by chance. :)

I think I only have one Dozier left. Maybe a little "Agent" that has got to be 15 to 20 years old. D2 is another steel that keeps cutting when it feels dull.

Joe

[araneae]

VG-10 does not have a carbide structure as fine as powder metallurgy products. I agree that CPM-154 would be in roughly the same property range.

Do you think a PM version of vg-10 would be worthwhile in terms of performance?

[Larrin]

Do you think a PM version of vg-10 would be worthwhile in terms of performance?

Maybe. It depends on what you are looking for. It's much cheaper to buy a steel that already exists like CPM-154 and it's questionable if there would be any real performance advantages over that steel. It's possible there would be a slight toughness advantage but there is no guarantee of that. VG10 has a bit less edge retention than 154. Probably isn't worth the cost of trying it.

[Eli Chaps]

Just read the December Spyderco Byte and I realized that they did the thing I was asking about by designing SPY27:
"Continuing this evolutionary path, the new Manix 2 Lightweight proudly features our proprietary CPM SPY27 blade steel. Starting with a tried-and-true Spyderco standard—Japanese VG-10 stainless steel—our goal was to enhance its alloy composition with the addition of nitrogen, niobium, and additional carbon and vanadium, and then produce the steel with the benefits of the particle metallurgy process. Working in close cooperation with Crucible Industries for more than a year of research and development, we were able to do exactly that."

Correct...from Spyderco's perspective, SPY27 is an upgraded PM version of VG-10.

What would the PM process in the same alloy bring to the table that would set it apart from the cast material? Finer grain size? It's already pretty tough so not sure there's ductility benefits but maybe.

Have a look at comparisons between ATS-34 and the powdered version RWL-34; or between 154-CM and the powdered version CPM-154. Smaller more uniform carbides, thus a tougher steel able to hold more acute angles.

My PM steel knowledge has a come long way since then. I have a far better understanding of the process and potential benefits than I did back then In fact, I'm now working in Powder metallurgy of other metals.