Call for Charpy toughness samples

I did Rc62 (aimed for a bit harder, but the results don’t lie) for the z-wear, as it’s intended use is to remain tough enough, even as you push up the hardness. These results show that it remains pretty consistent between different heat treat regimes and hardness. One could say it didn’t test that tough, but on the other hand, it was designed to be tougher and more wear resistant than D2, especially above Rc62, and in that comparison, it blows D2 out of the water. Combined with the fine edge stability, it’s head and shoulders above D2.

I will continue doing four tempers with z-wear, as the consistency of the samples was much tighter with each additional temper. It’s not a huge difference, but when I’m talking about a Rc62+ blade with 0.002-0.003” behind the edge, that slight nudge in the right direction might prevent a warranty return.

I was surprised by how poorly the cast cru-wear did. As I noted earlier, it performs similarity to z-wear in my test blades, but it was quite the difference in these tests. I was also surprised that there wasn’t much difference between 20cv and m390, and the m390 had coupons in both x and y axis from the milling direction. I expected to see more difference there.

We knew z-finit is tough, and it showed that in this test. I’m curious as to aeb-l at Rc62. How much does it lose when pushed that much harder.
 
JTknives said:
I am wondering if the AEBL results where just an anomaly. Alsi what is it’s toughness at the actual hardness people use it at. 59rc seams a little low for what I seen most people run there knives at. Seams like most people are pushing it into the 61-63rc range. I also think if 15n20 was tested at the same hardness as AEB-L it would have been up there with it in toughness. What would be really interesting would be a series of tests where each sample was tuned to have the same hardness. Then hardness becomes a moot point and we can see which steels came out tougher for X hardness.

But grate job on all the work and testing you have done.
Click to expand...

The one 15n20 sample at Rc61 tested at 23 lb ft, about the same as the better z-wear samples. That sounds about right to me, from real world experience using both steels. The z-wear has way better wear resistance though.

I don’t have any aeb-l on hand to test, but can get some for early next week, and try a few heat treats to see how it performs at Rc62.
 
I looked through the thread, and couldn’t see if anyone offered up some 1084. I’m curious as to how it would perform, to give us a frame of reference for these results. We’re comparing tough/not tough, but what is the standard we accept as “good”? I think seeing steels above or below a certain level makes more sense for a lot of us.

I’ve got some 9260 here as well, but it’s round stock. I’d have to forge it flat first.
 
1075 from the same batch of the sword that the gentleman who won Forged in Fire: knife or death made would be awesome, too! I know that sword is probably hardened in the low-mid 50’s (hard enough for me, toughness junkie), but not the cup of tea of most people here in the forum, I perfectly understand.
 
If there are data points that should be tried a list could be made and volunteers could pick one or 2 and send in the samples. Also if plans are for edge retention test a standard test blade blank could be added. I'm getting my oven soon and would be willing to add some samples.

Just a suggestion. If this thread is where the results are going to show they could be edited into the first page like the Ankerson test so they don't get lost in the middle . This thread might get kinda long:D
 
skillgannon said:
If there are data points that should be tried a list could be made and volunteers could pick one or 2 and send in the samples. Also if plans are for edge retention test a standard test blade blank could be added. I'm getting my oven soon and would be willing to add some samples.

Just a suggestion. If this thread is where the results are going to show they could be edited into the first page like the Ankerson test so they don't get lost in the middle . This thread might get kinda long:D
Click to expand...
All great suggestions!
 
Willie71 said:
I looked through the thread, and couldn’t see if anyone offered up some 1084. I’m curious as to how it would perform, to give us a frame of reference for these results. We’re comparing tough/not tough, but what is the standard we accept as “good”? I think seeing steels above or below a certain level makes more sense for a lot of us.

I’ve got some 9260 here as well, but it’s round stock. I’d have to forge it flat first.
Click to expand...

Hello, Willie71 Willie71 , my man Adam Kornalski (@Jamall) has some Vanadis 4 extra and A8mod leftovers, big enough for making three test coupons for each steel. Are you interested (or do you have the time) in heat treating it? If yes, he will ship it to you. If not, I perfectly understand!

Best regards!
 
hugofeynman said:
Hello, Willie71 Willie71 , my man Adam Kornalski (@Jamall) has some Vanadis 4 extra and A8mod leftovers, big enough for making three test coupons for each steel. Are you interested (or do you have the time) in heat treating it? If yes, he will ship it to you. If not, I perfectly understand!

Best regards!
Click to expand...


Sure, send it to me. Email me at wjkrywko at gmail dot com and I will send you my address.
 
Willie71 said:
Canada.
Click to expand...

I think I can also get enough NZ3 (~S1) steel to test. This will be interesting, because this steel is tough stuff and allegedly can reach 60hrc. The moment my makers send the steel, I’ll let you know, Warren! We should be able to make AEB-L biting dust.
 
This is fantastic, thank you!

I too would love to see 1084 as a benchmark at ~58Rc and ~62 to get some sort of standard, and also AEB-L at ~62 if folks get the chance.

My motivation is trying to standardize around 4 steels: simple and complex in both carbon and stainless. And then have a more explicit relative understanding of which to choose for a given use and their relative merits.
 
daizee said:
This is fantastic, thank you!

I too would love to see 1084 as a benchmark at ~58Rc and ~62 to get some sort of standard, and also AEB-L at ~62 if folks get the chance.

My motivation is trying to standardize around 4 steels: simple and complex in both carbon and stainless. And then have a more explicit relative understanding of which to choose for a given use and their relative merits.
Click to expand...
You should heat treat some samples!
 
Ok. I apologize for how long this has taken but I'm ready to process a bunch of coupons. A couple questions:

Can I engrave/scribe on the face of the coupon towards the edge (where a hole is OK) to identify them? What is the length of the "zone" this is OK in approximately?
3 coupons per alloy and heat treat procedure?
Is there a particular procedure (other than quench cryo temper) or particular hardness you would like me to shoot for? CPM M4, CPM 4V, Elmax, and I think I have CPM 3V as well. Additionally I'll do new stock 15N20 and W2. If there isn't something particular, I would like to send 2 sets of 3 coupons of the 4V in particular, with the same HT but one short (~1hr) cryo and one long (~12hr) cryo.
 
kuraki said:
Ok. I apologize for how long this has taken but I'm ready to process a bunch of coupons. A couple questions:

Can I engrave/scribe on the face of the coupon towards the edge (where a hole is OK) to identify them? What is the length of the "zone" this is OK in approximately?
3 coupons per alloy and heat treat procedure?
Is there a particular procedure (other than quench cryo temper) or particular hardness you would like me to shoot for? CPM M4, CPM 4V, Elmax, and I think I have CPM 3V as well. Additionally I'll do new stock 15N20 and W2. If there isn't something particular, I would like to send 2 sets of 3 coupons of the 4V in particular, with the same HT but one short (~1hr) cryo and one long (~12hr) cryo.
Click to expand...
Yes. Approximately 7mm per side.
At least 3.
I prefer at least 58 Rc. A range of hardness is optimal. 60 Rc is the approximate target we have had though some have been harder. The higher the hardness the more difficult it is to differentiate between steels and much lower than 60 is impractical for high end knives.
 
Well I've screwed up. I started with .110 stock thinking the small size and plate quench taking .005 per side would be sufficient to clean up. Its not. Im here finish grinding 18 samples that sit at .102" without one side fully cleaned up.

So Larrin Larrin are these of any value for the testing? I'm going to still hardness test them all and if you want them as is, or ground to .100, or ground to uniform clean up, let me know. Otherwise I'll order thicker bar and start over.
 
There may still be some utility in testing them. Especially if you have multiple heat treatments. The thickness may be close enough that we can divide by thickness and compare to the other tests, though with the understanding that the comparison is not perfect.
 
You must log in or register to reply here.
Back
Top