Competition Chopper M4, 3V, or Z-Wear

I understand the testing. I really need to find time to try different things. I think my first try will be with a standard austenizing, and cryo with low temp temper. Then I’ll go from there. Thanks guys for your help! I got my rc tester the other day, so now I can dial in my heat treat a little better! I just need a deware now!
 
It is difficult to really spend the time and materials to really do all the trials needed to verify an optimal HT approach for a particular steel in a particular application. I've only been able to do that with a few steels over the years, however 4V (V4E) is one of them.

The data sheet HT for 4V works well for tool and die where minimal crack risk and minimal growth from HT is important. But it makes a less durable edge that shows more damage in rough use and isn't ideal for knife.

4V turns out to be one of the steels that performs best with the low temper approach, like 3V and D2. This means you also need a relatively rapid quench and immediate cryo also (that's a part of that package deal, those things need to go together, skip part of it and none of it works).

I tested the low temp process that Peter's has for 4V and it actually works very well.

The data sheet HT for 4V isn't bad, but it isn't great.
 
Willie71 said:
Not worded quite right. High temper causes the precipitation, and slight decrease in toughness and corrosion resistance. Cryo/low temper prevents secondary carbide formation, which is slightly tougher and more corrosion resistant.
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I thought ETA and other precipitation carbides formed during tempering at temperatures lower than the secondary hardening bump, and after that are wiped out by the high temperatures.

The cryo-LTT allowed them to remain.
 
kuraki said:
I thought ETA and other precipitation carbides formed during tempering at temperatures lower than the secondary hardening bump, and after that are wiped out by the high temperatures.

The cryo-LTT allowed them to remain.
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The terminology is inconsistent. ETA carbides require cryo/low temper. Sub zero isn’t good enough. High temper gets what I refer to as secondary carbides, and the secondary hardening bump. Even if you use cryo, high temper erases eta carbides.
 
Ah ok. What Larrin referred to as transition carbides?
 
kuraki said:
Ah ok. What Larrin referred to as transition carbides?
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I believe so. I’ve seen the eta carbides called secondary carbides, and transition carbides called secondary carbides. Hopefully Larrin will set this straight so I can be correct in my use.
 
Kevin McGovern said:
View attachment 903137 This my first blade in 4v. It's for FIF, knife or death...maybe.
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Holy crap. That might just do it.

This thread got people going. I just bought a big stick of 3v last night.
Kevin McGovern said:
I would start with the data sheet. If you want to tweak the process for specific attributes, then have at it. I will say that I have been abusing this thing and the edge retention is impressive. It's a pain to sharpen though.
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Awsome knife. You probably already know this but on the off chance that you don't i will share. After diamonds spyderco ceramic stones cut just as fast as the diamonds. I have the sticks on th sharp maker but almost never use them any more. The bench stones are not that expensive. They do clog fast though and a large stone helps a lot. They cut M4 like butter so should work for you.
 
Nathan the Machinist said:
It is difficult to really spend the time and materials to really do all the trials needed to verify an optimal HT approach for a particular steel in a particular application. I've only been able to do that with a few steels over the years, however 4V (V4E) is one of them.

The data sheet HT for 4V works well for tool and die where minimal crack risk and minimal growth from HT is important. But it makes a less durable edge that shows more damage in rough use and isn't ideal for knife.

4V turns out to be one of the steels that performs best with the low temper approach, like 3V and D2. This means you also need a relatively rapid quench and immediate cryo also (that's a part of that package deal, those things need to go together, skip part of it and none of it works).

I tested the low temp process that Peter's has for 4V and it actually works very well.

The data sheet HT for 4V isn't bad, but it isn't great.
Click to expand...

Hello, Nathan, you do your own delta heat treatment, or Peters do it for you? I apologize if this was referred earlier in another thread.
 
I don't think Eta carbide and it's roles are well understood yet but here's my take on it.

Eta carbide would be a type of secondary carbide. It forms during temper in a matrix that was set up for it with certain cryogenic techniques. Although they aren't erased by higher tempers their effect on the matrix is. They're very small and very plentiful and their function in our application is to help pin slip planes but tempers over about 500f allows the matrix around them to relax enough that they essentially don't do anything.

I'd like to hear from Larrin on this.
 
The cryo literature has begun moving away from eta-carbides (transition carbides) and toward "secondary carbides" which are much larger. From a 2017 review: "Several later investigations have not been able to detect the presence of eta-carbide in cryotreated tool steels; this is expected because eta is a transition carbide and hence either dissolves or gets converted into stable cementite-carbide or alloy carbides." I'm not sure secondary carbides makes sense as an explanation either but that's what the literature says.
 
This remind me one of my regretful heat treat attempt, 1000f tempering on 3 blades made of spectrumwear... that end up 58HRC while XHP ht in the same batch got 62HRC from 400F tempering.
 
As said, M4 has been used by more competitors than any other steel. But perhaps might take a note from Keffeler, as he switched to Vanadis 4E.

I think in the end I would still come back to my beloved 3V. Especially now with the newest heat treat recipe I get from Brad. The blades I'm getting back from him at Peters are unreal! Was talking to Brad one day, and he said it right.... "If I was taking a trip to Mars with one blade, it would be CPM3V, that I heat treated!" I agree with him!

On a side note, I think it's humorous how certain members continue to mention "Knife or Death". Gee, I wonder who is sending the show an email each day to be chosen? LOL!! Just make sure y'all wear one of those really gay KILTS(Don't know why I was thinking Qilt... but spell chek'll get ya! Thanks Kevin), if you're chosen! ESPECIALLY if you're a fat tub of goo! It looks SOOOO cool! LOL!

I apologize to anyone offended by the overweight comment. I went from 225lbs(at 6'4"), to 278lbs since being disabled! So my comments ar times was a reflection on my disgust with my obesity. But a friend, brought the insensitivity to my attention. I don't think about people not knowing what I look like. It was a joke with no intended malice towards members, it was in fact very poor taste on the outside. Please accept my forgiveness.
 
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One Armed said:
As said, M4 has been used by more competitors than any other steel. But perhaps might take a note from Keffeler, as he switched to Vanadis 4E.

I think in the end I would still come back to my beloved 3V. Especially now with the newest heat treat recipe I get from Brad. The blades I'm getting back from him at Peters are unreal! Was talking to Brad one day, and he said it right.... "If I was taking a trip to Mars with one blade, it would be CPM3V, that I heat treated!" I agree with him!

On a side note, I think it's humorous how certain members continue to mention "Knife or Death". Gee, I wonder who is sending the show an email each day to be chosen? LOL!! Just make sure y'all wear one of those really gay quilts if you're chosen! ESPECIALLY if you're a fat tub of goo! It looks SOOOO cool! LOL!
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Why the hate? You have a problem with afghans too, or just quilts?
 
LOL! You're the only one that caught that Kevin! But yeah....blankets, sleeping bags and most forms of linens! They just burn me up!! Hahahahaha.


Of course, "K.I.L.T.S." Are A-OK! ;) Especially if you were to go with like an off PINK....
 
One Armed said:
LOL! You're the only one that caught that Kevin! But yeah....blankets, sleeping bags and most forms of linens! They just burn me up!! Hahahahaha.


Of course, "K.I.L.T.S." Are A-OK! ;) Especially if you were to go with like an off PINK....
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I'm going full on prom dress.
 
Hopefully I will be making a competition knife in Zwear for 2019. Still need to come up with a design and grind it out. But I will likely be using a low temper as suggested by Willie71 Willie71

Currently sent another camp knife there to test the low temper.
Willie71 Willie71 this should hopefully be an awesome test!
 
Nathan the Machinist said:
It is difficult to really spend the time and materials to really do all the trials needed to verify an optimal HT approach for a particular steel in a particular application. I've only been able to do that with a few steels over the years, however 4V (V4E) is one of them.

The data sheet HT for 4V works well for tool and die where minimal crack risk and minimal growth from HT is important. But it makes a less durable edge that shows more damage in rough use and isn't ideal for knife.

4V turns out to be one of the steels that performs best with the low temper approach, like 3V and D2. This means you also need a relatively rapid quench and immediate cryo also (that's a part of that package deal, those things need to go together, skip part of it and none of it works).

I tested the low temp process that Peter's has for 4V and it actually works very well.

The data sheet HT for 4V isn't bad, but it isn't great.
Click to expand...

Nathan,

When you say "relatively fast quench" are you talking aaa? also, when you refer to cryo, is DI bath cold enough, or is LN2 required?
 
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