BCMW ht 3V chopping tests

66rc W2 cleaver chopped 3 racks of pork back ribs (or maybe were from old sows because of lean meat & thick bones) into ~1" long pieces => first few lateral chops were worrisome but edge passed without any visible marks, except got a light patina.

Thinned the 63.5rc 52100 to 0.014" BET and sharpened 13dps. After 15 minutes of crazy chopping around - most of the time spent on a chunk of dried twisted knotty olive. Quite painful on the glove hand. Edge did fine - no visible marks nor reflect light.

Well, I got 3V data & enhanced ht params for impact toughness. Unless I get more thick 3V; spectrumwear and aebl bars for 63-65rc choppers AND OR questions/comments/requests, thread goes to Zzzz mode.
 
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65-66hrc is insane. How can you HT 3V to such a high hardness?
Would you mind me asking what is your austenitizing temp, quench media, tempering temp and any freeze treatment involved?
 
Sorry about vague ht params:

High aust temp but below 2250F; very fast cooling; cryo; tempered below 400F (untempered ~66.5rc).

According to my preliminary calculation, 3V max macro indentation hardness is around 67 +- 0.5 rc. Its high alloy volume% prevents hrc to reaches 68 +- 0.5 rc.

shqxk said:
65-66hrc is insane. How can you HT 3V to such a high hardness?
Would you mind me asking what is your austenitizing temp, quench media, tempering temp and any freeze treatment involved?
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bluntcut said:
Sorry about vague ht params:

High aust temp but below 2250F; very fast cooling; cryo; tempered below 400F (untempered ~66.5rc).

According to my preliminary calculation, 3V max macro indentation hardness is around 67 +- 0.5 rc. Its high alloy volume% prevents hrc to reaches 68 +- 0.5 rc.
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So the key is the higher aus temp. than factory recipe and uncommonly rapid quench right?

I always wonder if the very fast media like Park50 will get higher as quenched hardness than plate quench if both has identical aus temp.

I have had HT 3V at 2050 which is the maximum temp recommended by Crucible and I cracked all my blade quenching in molten salt before.
With even faster quench, do you ever have any problem with distortion, warpage or cracking?
 
Hints on what not to do but no 'how to' ht 3V to 66+rc (sorry).

2050F aust directly into p50 then cryo = most likely end up with warp & high RA%, i.e. AQ HRC probably be less than 63.
2150F aust directly into p50 then cryo = most likely end up with warp & even higher RA%, i.e. AQ HRC probably be less than 61.
2225F aust directly into p50 then cryo = most likely end up with warp+cracks; large grain size & crazy high RA%, i.e. AQ HRC probably be less than 58.

A box of loose lego(aust matrix) from different height onto the ground then shove into compactor (cryo) = a structure of low cohesion (aka a weak mart matrix).

Ht 3V according to specs - voi'la ready meals by designed < 65rc. I think D2 is a better high alloy steel for ht tinkerer because you can chase certain target result by following increment positive feedback loop.

btw with Super Quench w/o know what to do, could end up with warp blade, bacon cracked edge or 1-for-N-pieces.

shqxk said:
So the key is the higher aus temp. than factory recipe and uncommonly rapid quench right?

I always wonder if the very fast media like Park50 will get higher as quenched hardness than plate quench if both has identical aus temp.

I have had HT 3V at 2050 which is the maximum temp recommended by Crucible and I cracked all my blade quenching in molten salt before.
With even faster quench, do you ever have any problem with distortion, warpage or cracking?
Click to expand...
 
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Sound like I need to do other process beside what we normally do right? and also need to quench in high concentration brine which is the fastest quench media to achieved 66rc CPM-3V? I just don't get it seriously...

I don't know why you need to be so sneakingly about what you think you have known.

I think it would be good for you just to provide your HT recipe or what have you discovered about tinkering heat treat just like what Don Hanson, Davin Thomas, Rick Marchand, Cashen and many others did... You will get lots of admiration and will definitely benefit your business by a large margin.
 
shqxk said:
Sound like I need to do other process beside what we normally do right? and also need to quench in high concentration brine which is the fastest quench media to achieved 66rc CPM-3V? I just don't get it seriously...

I don't know why you need to be so sneakingly about what you think you have known.

I think it would be good for you just to provide your HT recipe or what have you discovered about tinkering heat treat just like what Don Hanson, Davin Thomas, Rick Marchand, Cashen and many others did... You will get lots of admiration and will definitely benefit your business by a large margin.
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Why give away the cow when you can sell the milk? Call Nathan Corothers, Peter's Heat Treating Services, or Dan Keffeler and see if they'll tell you the specific heat treatment protocols they spent a long time working on. Last time I saw someone ask Nathan he was a little perturbed that someone assumed that he'd give away that info. He gave his goals and general thoughts but specifics are a no no.

Call crucible and ask them the specific ingredients of knife steels they're currently experimenting with but haven't really put onto the market yet.

The reason Kevin Cashen gives his info away is because he's a huge proponent of following the industry standard hear treatments and scoffs at anyone who deviates much. He's pretty vocal about it, too. Devin Thomas and Don Hanson sell knife steel so I'd hope they'd tell people how to harden what they sell.

That and I think Luong enjoys tinkering and experimenting with this stuff and doesn't want to put out any info that might not be 100% spot on. He also likes to put what he's working on on display so that people can see progression and see for themselves that certain things can be done that wasn't thought possible. Like stable 3V at 66 RC or 65 RC D2. Hopefully that gets other people tinkering too. Not me, I'm not that into it, but it's cool seeing someone that's not afraid to show the rabbit hole that metallurgy is and how much can be done that's not currently being done.
 
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bodog said:
Why give away the cow when you can sell the milk? Call Nathan Corothers, Peter's Heat Treating Services, or Dan Keffeler and see if they'll tell you the specific heat treatment protocols they spent a long time working on.
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This is not about giving a cow my friend... Don Hanson has give community his W2 recipe for years... Same as Cashen, Marchand, Adam DessRossier and many others maker. All of them still run their business with success, the more you give the more you get... ya know.

What bluntcut have did is something different. I know there are some people who doubt about how CPM-3V can even achieve 66rc as quenched hardness. It sound very illogical for me to the point that is unbelievable. Even you have the video of HRC tested and I still doubt about the accuration of the tester...

66.6hrc can be reasonable as quenched of steel like W2 or 1095 but for CPM-3V it is just meh to me.

And I have talked with Keffeler via Facebook and he give me the CPM-3V HT recipe but it not 66rc AQ... That are why I asking here.
 
shqxk said:
This is not about giving a cow my friend... Don Hanson has give community his W2 recipe for years... Same as Cashen, Marchand, Adam DessRossier and many others maker. All of them still run their business with succeed, the more you give the more you get... you know.

What bluntcut have did is something different. I know there are some people who doubt about how CPM-3V can even achieve 66rc as quenched hardness. It sound very illogical for me to the point that is unbelievable. Even you have the video of HRC tested and I still doubt about the accuration of the tester...

66.6hrc can be reasonable as quenched of steel like W2 or 1095 but for CPM-3V it is just meh to me.

And I have talked with Keffeler via Facebook and he give me the CPM-3V HT recipe but it not 66rc AQ...
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It sounds pretty crazy to me too. I hope that eventually Luong stops experimenting and sends two knives, one with industry standard heat treatment and another with his version, to a real testing facility who will dissect his work and prove or disprove what he's saying. Some of his claims really are bold. Until someone can disprove it, though, why question him? He's providing some simple proofs along the way and hasn't shied away from sending samples out for people to test. Hell, I suggested him making a video of hardness testing and he was quick to show his setup. I don't think he's hiding anything.

Personally I'd love to see a double blind test done by someone who knows how to really test knives. Kevin Cashel may be a guy who can do it. The knives would have to be ground and there'd have to be multiple examples of the same steel, ground the same way, with the same dimensions, heat treated by different people, and then sent to the tester without the tester having the slightest idea of who did what. That'd be the only true way to see. Abrasive and adhesive wear resistance, impact toughness, lateral strength, hardness, etc., accompanied by electron microscope photos of the grain and matrix structure.
 
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bodog said:
It sounds pretty crazy to me too. I hope that eventually Luong stops experimenting and sends two knives, one with industry standard heat treatment and another with his version, to a real testing facility who will dissect his work and prove or disprove what he's saying. Some of his claims really are bold. Until someone can disprove it, though, why question him? He's providing some simple proofs along the way and hasn't shied away from sending samples out for people to test. Hell, I suggested him making a video of hardness testing and he was quick to show his setup. I don't think he's hiding anything.
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Yeah, I think he is a very good and knowledgeable guy. I always take his word as a fact since 3 years ago when he post his steel testing with humble sense and unbiased opinion.

I just think he might discover something very interesting on heat treating science that could be turn up the whole knife making community. But unless he prove it with third party people, there will be some people (properly many people) who skeptical on what he did.

It wouldn't be very beneficial for him to hide it. I don't see his knife selling around very often. In fact, I never seen one before...

I believed he invested his time doing so much about tinkering to improve and experiment on heat treating, at least he should get something back.
 
Thanks guys.

I share 1) what are possible beyond conventional ht. 2) willing to provide guidance/hints to those want to learn and asking good questions in your working context.

If you want to learn 'what & why', start here - https://en.wikipedia.org/wiki/Burgers_vector. Solutions to problem = many route to 'how'.

edit: edge is just a very convenient way to test very thin cross section of steel.
 
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Bodog - thanks for good suggestions in formal test ht steels. My early attempts with external metallurgical examination, BSED shown a clear trail of what I tried to do, thus wearied am.

Yesterday, I wrote in an email equate solving matrix structure problems (cohesion, congruence, coherence sum) as LA, DE, CV (Linear Algebra, Diff Eq, Complex Vars). As rusty as I am with Math & Physics, I think I've made only a very small progress.
 
As stated earlier, I need a piece of data for ~65rc 3V in impact toughness. Got that done. Shared result. Now I am back on low Cr high carbon steels track.

Whether 3V can hits 66+rc AQ, tester accuracy, videos are real or computer generated, marketing garbage, so on... skeptical is wise:thumbup:

btw (marketing) - boy pic & book in sig are real - proven so :p

shqxk said:
This is not about giving a cow my friend... Don Hanson has give community his W2 recipe for years... Same as Cashen, Marchand, Adam DessRossier and many others maker. All of them still run their business with success, the more you give the more you get... ya know.

What bluntcut have did is something different. I know there are some people who doubt about how CPM-3V can even achieve 66rc as quenched hardness. It sound very illogical for me to the point that is unbelievable. Even you have the video of HRC tested and I still doubt about the accuration of the tester...

66.6hrc can be reasonable as quenched of steel like W2 or 1095 but for CPM-3V it is just meh to me.

And I have talked with Keffeler via Facebook and he give me the CPM-3V HT recipe but it not 66rc AQ... That are why I asking here.
Click to expand...
 
Hey bluntcut, i didn't mean to offend you. I'm actually always respect your effort and knowledge...

I have HT 3V by my self before with 500F molten nitrate salt and cryogenic.

With the maximum aus temp 2050F which recomended by Crucible I can only achieved 63rc. I have tried park50 quench and it cracked... Too rapidly quench will only give lower hardness due to the RA.

From my knowledge and experience higher alloy = higher hardenability and deeper depth of hardness. But lower maximum as quenched hardness.
Grain size does effect the hardenability and depth of hardening too. It can be see clearly when working with hamon (W1, W2, 1095). If you need to do 2nd or 3rd quench the hamon line will get lower to the edge.

W2 can get maximum AQ at 66rc,
52100 = 65rc
A2 = 63-64

This is what I have actually seen by myself. As you can see the higher alloy = lower as quench hardness when carbon amount is similar.

The as quench of CPM-3V at 66rc is just blow my mind... and I don't think I have enough knowledge to apply Burgers vector to improve my heat treatment.
 
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Thank you. However no offense taken, gotta have thick skull & skin to posts here.

Alloying elements/wheel help to get going but quickly burn up on a ht racing track :p

wnd_77a10746bee4086f65846d5c2ff05f1e.jpg


It's no secret - high alloy% + high dislocation == intrinsic high RA. HRC is a pseudo measure of strength via macro indentation. This 2 together blocked many from seeing the true nano hardness. There is varying degree in nano, 30-100nm is the range of my interest. RA & severe macro dislocation prevent you from getting higher 3V AQ hrc.

Face the challenge of testing untempered matrix, think & improve ht params until peak = working nano hardness. When macro is barely higher than nano indentation #, congrats & please share with me :D

shqxk said:
Hey bluntcut, i didn't mean to offend you. I'm actually always respect your effort and knowledge...

I have HT 3V by my self before with 500F molten nitrate salt and cryogenic.

With the maximum aus temp 2050F which recomended by Crucible I can only achieved 63rc. I have tried park50 quench and it cracked... Too rapidly quench will only give lower hardness due to the RA.

From my knowledge and experience higher alloy = higher hardenability and deeper depth of hardness. But lower maximum as quenched hardness.
Grain size does effect the hardenability and depth of hardening too. It can be see clearly when working with hamon. If you need to do 2nd or 3rd quench the hamon line will get lower to the edge.

W2 can get maximum AQ at 66rc,
52100 = 65rc
A2 = 63-64

This is what I have actually seen by myself. As you can see the higher alloy = lower as quench hardness when carbon amount is similar.

The as quench is CPM-3V at 66rc is just blow my mind... and I don't think I have enough knowledge to apply Burgers vector to improve my heat treatment.
Click to expand...
 
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On my beach walk, I found a shell - below. Maybe it could helps visualizing matrix microstructure optimization.

Structure
Cohesion = spacing
Congruence = radial lines
Coherence = clarity of pattern

LVKl92d.jpg
 
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Here is a rough idea, which could answer a couple 3V curiosities: 1) AQ 66rc 2) edge stability at 65rc

Someone send a knife maker (Receiving KM) near my area:

1) a hardness tester ~62rc calibration block, unless this receiving KM already have a block for ~62rc.

2) 2x identical 3V knife/chopper w/o handle, where 1 hardened (preferable by Peters or Nathan) to whatever working hrc, 1 unhardened.

In addition RKM - provide a clean grounded 3V coupon (1" x 3" at least 1/8" thick)

This RKM swing by my place
a) 8AM: drop off the unhardened blade & coupon. Then R&R around the Goleta Beach for few hrs.

b) 1:15PM - enjoy lunch together at Beach Cafe

c) 2:30PM - video hardness testing for: brought along calibration + my blocks; 2 3V blades and the coupon. Exit while I lower the BCMW ht 3V to ~65rc

d) 2:45PM (didn't temper long - hahaha): Video quick hrc reading for 2 3v blades again

e) Video side to side performance of the 2 blades. RKM welcome to bring chopping materials - something hard and challenging but no silliness stuff (like I have in some videos); change hands a few times. Zoom in.

f) Take macro pics of the 2 blades.

g) Make copy for videos & Pics.
h)
option 1: toss BCMW ht blade & coupon into 1500F oven for 10 minutes <= ERASE!
option 2: Pay $500 to keep BCMW ht 3v blade, extra $100 for 66-66.5rc 3v coupon. LOL - this option2 is moot if my ht is lousy, right?

So $ needed for: 2 buy/borrow blades, RKM time, lunch, plus potential $600 for keeping BCMW ht.

Even $1K ticket is so cheap compare to my R&D expenditure.

Disseminate videos & pics to participants. With my & RKM consents, videos & pics can be share on BF by RKM and or myself.

Thoughts/suggestions?
 
If anyone is doubting as quenched hardness of 66, this is pretty close.

4.jpg~original


^ That's here in my shop on an NIST traceable, certified and calibrated hardness tester. That includes subzero as a part of the quench. I'd consider 3V at HRC 66 to be very possible and simply on the high side of normal.

I'd be glad to send a 3V chopper at HRC 60.5 and Field Knife at HRC 62.0 for experimenting, though if it's going to be compared to someone else's work I'd like the opportunity to reciprocate. :thumbup:
 
I'm glad with the progress and sharing. Earlier I was skeptical that any maker will be willing to test it out with Luong.

Looking forward to Luong & Nathan's test / comparing notes. :thumbup:
 
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