Toughness testing – Cru-Wear, Z-Wear, Upper vs Lower temper, Cryo vs No Cryo

Larrin

Larrin

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New article summarizing and describing toughness testing done with Warren (Willie71) where we compared Cru-Wear (ingot steel) with Z-wear (PM steel), upper and lower tempers (400 vs 1000°F), with and without cryo, and also different lengths of time at cryo (1h, 12h, and 36h). Lots of good stuff in here.

http://knifesteelnerds.com/2018/06/04/toughness-testing-cru-wear-z-wear/
 
Very interesting.
I'll have to see what they favor.
DeadboxHero said:
ShannonSteelLabs ShannonSteelLabs

Check this out Collin
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I will be testing this steel much further than i have before. I plan on making a Competition knife out of Zwear.
Seems like cryo doesnt have a massive effect on toughness for this steel. I will likely use cryo to maintain the edge holding. I will be in contact with Brad at PHT, i ran into him and spoke for a while at blade this past weekend.
 
Im thinking of using cryo and the low temper to get 60.5 or 61.5.
Seems like that combo will give me the toughness and edge holding i need.

Currently i use 62HRC from peters. It has cryo, and i assume the high tempers. I'll have to find out.
 
I love this steel. I just finished a 3V sample at about Rc62, to compare to the z-wear toughness.

Don’t be worried about going Rc62, or even higher with this steel. Remember competition choppers in M4 are in the Rc64 Range, and that steel isn’t as tough as this stuff.

In steels like 3V, the cryo/low temper is used to help the microchipping or mushy edges these steels have been criticized for. That difference might not show much on this type of test, but those extra lb ft might be that difference.
 
It's a fantastic balance. I will try to get my coupons done this weekend, as I would really like to see how 4V compares, as I think the two are about the best balance between wear/tough that I've laid hands on.
 
Well screw it maybe i'll go for 63 HRC!!!
Seen a few competitors go to 63 with CPM 4V.

Would you reccomend what i had said? Cryo plus low tempers?
Willie71 said:
I love this steel. I just finished a 3V sample at about Rc62, to compare to the z-wear toughness.

Don’t be worried about going Rc62, or even higher with this steel. Remember competition choppers in M4 are in the Rc64 Range, and that steel isn’t as tough as this stuff.

In steels like 3V, the cryo/low temper is used to help the microchipping or mushy edges these steels have been criticized for. That difference might not show much on this type of test, but those extra lb ft might be that difference.
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ShannonSteelLabs said:
Well acrew it maybe i'll go for 63 HRC!!!
Seen a few competitors go to 63 with CPM 4V.

Would you reccomend what i had said? Cryo plus low tempers?
Click to expand...

I’ve run blades up to Rc64/65 (in kitchen knives) and Rc63/64 for edc knives. I’ve done camp knives at Rc61/62, and ZERO of them have been sent back with edge damage. I’d go Rc63, cryo/low temper. If you go down to the Rc60/61 range for toughness, you might as well go with 3V.
 
kuraki said:
It's a fantastic balance. I will try to get my coupons done this weekend, as I would really like to see how 4V compares, as I think the two are about the best balance between wear/tough that I've laid hands on.
Click to expand...
Are you doing one heat treatment or a range of hardness?
 
Should I do z-wear at 1975 and 2000f, cryo, low temper to see how much toughness drops off?
 
Willie71 said:
I’ve run blades up to Rc64/65 (in kitchen knives) and Rc63/64 for edc knives. I’ve done camp knives at Rc61/62, and ZERO of them have been sent back with edge damage. I’d go Rc63, cryo/low temper. If you go down to the Rc60/61 range for toughness, you might as well go with 3V.
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Alright 63 HRC with cryo and low temper. gonna order some soon in 0.290 stock.
Thanks for the reccomendation!
 
If wishes were fishes I’d want Vanadis 4 at 60, 62, and 64 Rc.
 
Sorry I mean 4V. Need to keep my brand names straight.
 
glad to see this thread as i has seen the graph a bit late to talk aboit it. i was sshocked that the Zware more less mzxed out its toughness no matter the hardness or cryo or not while the cruforge showed what i expected as a drop in strength ad hardness went up. do you think this is more due to the PM process
 
butcher_block said:
glad to see this thread as i has seen the graph a bit late to talk aboit it. i was sshocked that the Zware more less mzxed out its toughness no matter the hardness or cryo or not while the cruforge showed what i expected as a drop in strength ad hardness went up. do you think this is more due to the PM process
Click to expand...
I don't think it's because of PM, since datasheets from Crucible and Bohler-Uddeholm show a stronger effect of hardness on toughness. More likely we just need to use different heat treatment parameters to see an increase in toughness with lower hardness.
 
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