Heat Treatment - Crystal Weaving Foundation

bluntcut said:
For 15V would martempring yields 69+rc and edge chip instead of blade-crumble when chop 16d nail? Could be that no one try before ;)
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I'm not sure that other people have tried Martempering 15V ( or most of the new steels)
Your results are pretty exciting up to now
 
Revolverrodger said:
I'm not sure that other people have tried Martempering 15V ( or most of the new steels)
Your results are pretty exciting up to now
Click to expand...

I don't know exactly what Luong is doing to yield the results he's seeing but he really is producing what he says he's producing. I'm pretty critical about a lot of things but Luong's heat treatment isn't one of them. He's gone through multiple phases and I've experienced thick stock 52100 ground to a thin edge and it was dynamite in hard use. I don't see many people doing the crap I was doing with it on a daily basis. He provided a thin 52100 kitchen knife and I beat the crap out of it and the only thing that really caused significant damage was smacking the knife into glass jar rims. I did some minor testing of W2 and 80CrV2 and they held up very well. I was satisfied that he could do some good work with low chromium steels.

Fast forward and I've used 10V at 68 Rockwell as a daily random user (mainly kitchen). I threw a handle on it. I HAVE whittled rib bones and purposefully cut against porcelain and ceramic. This knife is as thin as a fillet knife and I haven't needed to sharpen it at all since the initial job I did a couple of months back. Is it hair whittling? Not at this point, no. But it still cuts and cuts well. I've been waiting until I needed to sharpen it to make a real testament about it but after months of purposefully negligent and frankly dickheaded treatment it's not needed it yet. I'm not exactly sure when it will need it. I've been considering sharpening it but it doesn't need it yet.

He also provided a 15V blade at 70 RC. I haven't tested it yet but it's obvious where it was tested for hardness on the tang. Luong had shown videos where his hardness tester isn't in question. He sent blades to other well known bladesmiths and they independently tested his knives and were impressed with both the hardness and the blade's capabilities. This is knifemaker known for what they've done with 3V and getting Peter's Heat Treating to change what they're doing.

It HAS been independently tested by multiple people and has been found to be true. I'm not known for being the nicest person about knife maker's faults and Luong is genuine when he says something. Take it for what it's worth.

Yes, his results are exciting. No, others aren't doing what he's doing. And yes, he's sincere and genuine. He's very clearly putting the results of his efforts on full public display. He's been ridiculed for a long time and it's only been recently that others have really seen what he's accomplishing. Those who have been watching what he's been doing for awhile are excited not just for him, but for the entire knife industry as a whole.

I'm not well liked for being the nicest guy who minces words or says things in the nicest manner. Luong deserves recognition for what he's been doing. 15V at 70 RC only chipping when striking a nail is downright impressive. The fact it didn't break is pretty crazy. Luong is on to something whether other people want to fully admit it or not.

The only bad thing I could possibly say is that what's he's doing basically erases any kind of corrosion resistance a steel may have. But that's not the point of what he's doing and I accept it.

His grinds on his test knives aren't the best but they're test knives, after all. That's all I can really vouch for as far as aesthetics. The performance has been really great given specific steels. I have no problem using or carrying whatever he comes up with. I cannot say the same for multiple other makers.
 
Russ/bodog,

I am very appreciative of your kind words and ... you tossed me in this 15V tornado by offered me 2x 15V free bars to tinker with (but my timing didn't worked out). If that wasn't enough, yours offer of Ringed Gidgee wood for knife handle followed. You certainly don't mince words and your offers are beyond words :thumbup:

Just a quick correction about corrosion resistance from cwf ht. The black stuff you see on this test 15v chopper (and your 15V too) is just burned-oil during quench. Just soak in vinegar overnight would shed all that. Cwf ht actually leave most Cr avail for corrosion resistance because it austenite at middle to upper range of temperature, thus dissolved most CrxCy (freeing Cr). And low tempering temperature so Cr stay free. Unlike other ht use secondary tempering, that is when Cr7C3 precipitate (no longer avail to passivate).

Truth/true to myself is the most rewarding learned+required aspect from 8+yrs journey putting together the book (in my signature). I have same perspective in ht/metallurgy - when truthful, there is no need to keep track of lies/deceptions. Sure, I am at times overly optimistic/delusional stemmed from combination of misguided; lacked of skills; so on. Yup, it's learning in progress...

bodog said:
I don't know exactly what Luong is doing to yield the results he's seeing but he really is producing what he says he's producing. I'm pretty critical about a lot of things but Luong's heat treatment isn't one of them. He's gone through multiple phases and I've experienced thick stock 52100 ground to a thin edge and it was dynamite in hard use. I don't see many people doing the crap I was doing with it on a daily basis. He provided a thin 52100 kitchen knife and I beat the crap out of it and the only thing that really caused significant damage was smacking the knife into glass jar rims. I did some minor testing of W2 and 80CrV2 and they held up very well. I was satisfied that he could do some good work with low chromium steels.

Fast forward and I've used 10V at 68 Rockwell as a daily random user (mainly kitchen). I threw a handle on it. I HAVE whittled rib bones and purposefully cut against porcelain and ceramic. This knife is as thin as a fillet knife and I haven't needed to sharpen it at all since the initial job I did a couple of months back. Is it hair whittling? Not at this point, no. But it still cuts and cuts well. I've been waiting until I needed to sharpen it to make a real testament about it but after months of purposefully negligent and frankly dickheaded treatment it's not needed it yet. I'm not exactly sure when it will need it. I've been considering sharpening it but it doesn't need it yet.

He also provided a 15V blade at 70 RC. I haven't tested it yet but it's obvious where it was tested for hardness on the tang. Luong had shown videos where his hardness tester isn't in question. He sent blades to other well known bladesmiths and they independently tested his knives and were impressed with both the hardness and the blade's capabilities. This is knifemaker known for what they've done with 3V and getting Peter's Heat Treating to change what they're doing.

It HAS been independently tested by multiple people and has been found to be true. I'm not known for being the nicest person about knife maker's faults and Luong is genuine when he says something. Take it for what it's worth.

Yes, his results are exciting. No, others aren't doing what he's doing. And yes, he's sincere and genuine. He's very clearly putting the results of his efforts on full public display. He's been ridiculed for a long time and it's only been recently that others have really seen what he's accomplishing. Those who have been watching what he's been doing for awhile are excited not just for him, but for the entire knife industry as a whole.

I'm not well liked for being the nicest guy who minces words or says things in the nicest manner. Luong deserves recognition for what he's been doing. 15V at 70 RC only chipping when striking a nail is downright impressive. The fact it didn't break is pretty crazy. Luong is on to something whether other people want to fully admit it or not.

The only bad thing I could possibly say is that what's he's doing basically erases any kind of corrosion resistance a steel may have. But that's not the point of what he's doing and I accept it.

His grinds on his test knives aren't the best but they're test knives, after all. That's all I can really vouch for as far as aesthetics. The performance has been really great given specific steels. I have no problem using or carrying whatever he comes up with. I cannot say the same for multiple other makers.
Click to expand...
 
From my point of view, There are two mistake bluntcut has made which make this thread not very popular to others makers or many people who interest metallurgy.

1. He rush to name this HT procedure to a fancy and no certainly logic behind it like Crystal Weaving Foundation. If he just named this method into some metallurgy approved word like dynamic marquenching with continuous cryogenic etc. it would be a different story.

2. He start this thread in General Discussion. He clearly a knife maker and I'm not sure why heat treatment thread are not belong to knife maker sub forum beside felt that he just want to advertising it or avoid others maker to questioning it?

Actually people like bluntcut is what community need in order to discover newer invention/innovation... A guy who think out of the box seeking for something better. Who knows one day in the future what he discovered in this thread will make a big change the industry and defy old metallurgy about heat treatment in the future.
 
bluntcut said:
Russ/bodog,

I am very appreciative of your kind words and ... you tossed me in this 15V tornado by offered me 2x 15V free bars to tinker with (but my timing didn't worked out). If that wasn't enough, yours offer of Ringed Gidgee wood for knife handle followed. You certainly don't mince words and your offers are beyond words :thumbup:

Just a quick correction about corrosion resistance from cwf ht. The black stuff you see on this test 15v chopper (and your 15V too) is just burned-oil during quench. Just soak in vinegar overnight would shed all that. Cwf ht actually leave most Cr avail for corrosion resistance because it austenite at middle to upper range of temperature, thus dissolved most CrxCy (freeing Cr). And low tempering temperature so Cr stay free. Unlike other ht use secondary tempering, that is when Cr7C3 precipitate (no longer avail to passivate).

Truth/true to myself is the most rewarding learned+required aspect from 8+yrs journey putting together the book (in my signature). I have same perspective in ht/metallurgy - when truthful, there is no need to keep track of lies/deceptions. Sure, I am at times overly optimistic/delusional stemmed from combination of misguided; lacked of skills; so on. Yup, it's learning in progress...
Click to expand...

"If you tell the truth, you don't have to remember anything." -Mark Twain

One of my favorite quotes! :D
 
shqxk said:
From my point of view, There are two mistake bluntcut has made which make this thread not very popular to others makers or many people who interest metallurgy.

1. He rush to name this HT procedure to a fancy and no certainly logic behind it like Crystal Weaving Foundation. If he just named this method into some metallurgy approved word like dynamic marquenching with continuous cryogenic etc. it would be a different story.

2. He start this thread in General Discussion. He clearly a knife maker and I'm not sure why heat treatment thread are not belong to knife maker sub forum beside felt that he just want to advertising it or avoid others maker to questioning it?

Actually people like bluntcut is what community need in order to discover newer invention/innovation... A guy who think out of the box seeking for something better. Who knows one day in the future what he discovered in this thread will make a big change the industry and defy old metallurgy about heat treatment in the future.
Click to expand...

I don't believe that he discovered any new magical state of steel (crystal weave) , but rather has applied unusual HT methods (martempering) to new steels (s110v) etc...
I hope other people with the proper facilities continue his testing
 
shqxk said:
From my point of view, There are two mistake bluntcut has made which make this thread not very popular to others makers or many people who interest metallurgy.

1. He rush to name this HT procedure to a fancy and no certainly logic behind it like Crystal Weaving Foundation. If he just named this method into some metallurgy approved word like dynamic marquenching with continuous cryogenic etc. it would be a different story.

2. He start this thread in General Discussion. He clearly a knife maker and I'm not sure why heat treatment thread are not belong to knife maker sub forum beside felt that he just want to advertising it or avoid others maker to questioning it?

Actually people like bluntcut is what community need in order to discover newer invention/innovation... A guy who think out of the box seeking for something better. Who knows one day in the future what he discovered in this thread will make a big change the industry and defy old metallurgy about heat treatment in the future.
Click to expand...
:thumbup: Thanks for well thought out rational feedback points. They are valid however I will clarify (not countering) each point a tiny bit

1. One often give a concept/approach name. Clearly most disagreed that this it a new concept and preferred calling combination of marquench & martemper. I still think, it is a new concept and barely started.

2. Shop Talk is an excellent place to discuss & share know-hows in knife making but very hostile to unconventional new ideas. I avoided that battle.


Mecha said:
"If you tell the truth, you don't have to remember anything." -Mark Twain

One of my favorite quotes! :D
Click to expand...
:thumbup:

Revolverrodger said:
I don't believe that he discovered any new magical state of steel (crystal weave) , but rather has applied unusual HT methods (martempering) to new steels (s110v) etc...
I hope other people with the proper facilities continue his testing
Click to expand...
A few posts up ^^^^^^ 52100/W2/O1/Cfv - maybe this ht is applicable a bit more than just new steels ;)
 
bluntcut said:
2. Shop Talk is an excellent place to discuss & share know-hows in knife making but very hostile to unconventional new ideas. I avoided that battle.
Click to expand...

@shqxk,

Luong has tried previously discussing in Shop Talk, but got hostility directed to him.
I wish others try what he has shared, and if possible and having more equipment, validate the hypothesis... That's the only way forward and it will definitely benefit more than just knife making.

Luong,

You mentioned that 15V with CWF has adequate strength to hold the structure when chopping as in the video, and the wood / bone simply has to move away (read: break off) instead of steering the edge, i.e. the bone/wood structure strength gives way to the steel strength. So in this case, having higher strength protects the high carbide nature making it no longer chippy in normal (or heavy) use. It means toughness (i.e. rolling) isn't needed in this case.
I recalled you've been chasing high strength for a long time ... :cool: :thumbup:
 
Hello.
I do not usually post, because it is not worth trouble, but this is so interesting, I had to tell my opinion.
If all told the heat treatment is correct, I feel it is not martempering but also not anything that cannot ex-plain current knowledge.
When steel is cooled so slow (after pearlite curve), there will be some lover bainite and martensite. But if it is correct, that the steel is quite soft still after cryo, there is lots and lots of retained austenite.
Then when the steel is tempered (I feel like to say tempering, even it is shorter time than normal tempering), steel starts precipitate carbides and the remaining metastable austenite suddenly activate and starts transforming martensite.
So final transformation happens high temperature, which is great. Transformation will be even (less stress) and steel also will be very tough and allow more movement during transformation. Also if cooled slowly after tempering the fresh martensite will also be slightly tempered before coming room tempera-ture. Also there might still be left some more stabile austentite.
So the steel is never stressed being untempered fully martensitic at room temperature. That could explain its properties.
This is only my opinion/guess/theory so do not take it too seriously. I do not want to argue with anyone.
It would be interesting to know, if the blade will be given after that one more conventional tempering, will it still be better or same than steel whit all more conventional heat treatment.
Sorry language mistakes

Matti S.

Edited many times
 
Last edited:
Thanks, Chris!

High strength is a given attribute for high alloy steels however they have low impact load (toughness in term of load). A big component of my pursue in strength & toughness defined by - Hall–Petch strengthening https://en.wikipedia.org/wiki/Grain_boundary_strengthening. For 1*V to have good impact load, grain refinement maybe adds extra 60% role, 40% of non-disclosed something else. My video demo of 64rc D2 chopper shows good impact load is possible even for very well known brittleness attribute of D2 especially at high hardness.

When I seen/encountered evidences that don't make sense or at odd against conventional/current/as-of-understanding life/science/so-on. If evidences passed qual+quan analytical scrutiny, then I would be curious about what+why+how. Evidences don't have to prove anything but their existence might be all that need to be.

As example: This 70rc 15V blade heat treated with grain refinement (GR). GR sounds suspicious, thereby combination of 1. (skeptical) maybe Luong's dishes out misdirection or 2. (blast it) BS because it can't possibly be done or 3. is it possible and how the heck was done? or xyz. Furthermore, does GR contributes anything to this 15V chopper? I think, Yes because I have tested 10V & S90V with & without GR in impact load - those w/o GR definitively shown low impact load. If this GR point raises in Shop Talk, it would drown by option 2. until I proven or disclose otherwise. I respectfully avoided this battle.

Chris "Anagarika";16922523 said:
@shqxk,

Luong has tried previously discussing in Shop Talk, but got hostility directed to him.
I wish others try what he has shared, and if possible and having more equipment, validate the hypothesis... That's the only way forward and it will definitely benefit more than just knife making.

Luong,

You mentioned that 15V with CWF has adequate strength to hold the structure when chopping as in the video, and the wood / bone simply has to move away (read: break off) instead of steering the edge, i.e. the bone/wood structure strength gives way to the steel strength. So in this case, having higher strength protects the high carbide nature making it no longer chippy in normal (or heavy) use. It means toughness (i.e. rolling) isn't needed in this case.
I recalled you've been chasing high strength for a long time ... :cool: :thumbup:
Click to expand...
 
Matti - your insights are appreciated!

Inlines are from my understanding of metallurgy - hence read with healthy skepticism.

Matti S. said:
Hello.
I do not usually post, because it is not worth trouble, but this is so interesting, I had to tell my opinion.
If all told the heat treatment is correct, I feel it is not martempering but also not anything that cannot ex-plain current knowledge.
Click to expand...
Agree

When steel is cooled so slow (after pearlite curve), there will be some lover bainite and martensite. But if it is correct, that the steel is quite soft still after cryo, there is lots and lots of retained austenite.
Click to expand...
If lower bainite transformation taken place (LB%), consists of cementites & ferrite. HRC of lowest bainite is around 58, so if LB% is more than 5 percent, overall hardness of this 15V probably won't reach 65rc. Well, cooling time window is too small for LB to take place for 15V CCT, good chance LB doesn't apply here. Per my video on CWF HT, RA is high by concept of crystal structure which induced high dislocation preventing aust to mart conversion. While cooling in conventional ht is a race condition to convert aust to mart depend on deactivation energy and spatially permitted - in this case hardness is peak after cryo but brittle.

Then when the steel is tempered (I feel like to say tempering, even it is shorter time than normal tempering), steel starts precipitate carbides and the remaining metastable austenite suddenly activate and starts transforming martensite.
Click to expand...
Diffusionless precipitation produces mostly cementite and ferrite, ignoring(keep it simple) complex nano structure particle types. Activation energy (envision climbing out of a crater with a ledge and a ridge/lip) for aust to mart is lower than precipitation - analogous to a ledge. Thermal + dislocation/stress = precipitation can taken place at low temperature (even when warming up from cryogenic).

So final transformation happens high temperature, which is great. Transformation will be even (less stress) and steel also will be very tough and allow more movement during transformation. Also if cooled slowly after tempering the fresh martensite will also be slightly tempered before coming room tempera-ture. Also there might still be left some more stabile austentite.
So the steel is never stressed being untempered fully martensitic at room temperature. That could explain its properties.
Click to expand...
You are right, thermal expansion allows more room/space for aust to mart conv. btw - I call 275F activation temperature, rather than mixing/confusing up with traditional use of tempering term. I view, 'stabilized austenite/RA' is more less a liability for impact interactions = crack nucleation/propagation points when activated by stretch/flex and impact. RA can be useful but 'stabilized RA' are weakness of the matrix.


This is only my opinion/guess/theory so do not take it too seriously. I do not want to argue with anyone.
It would be interesting to know, if the blade will be given after that one more conventional tempering, will it still be better or same than steel whit all more conventional heat treatment.
Click to expand...
Depend on carbide volume, some CWF HT blades receive tempering with temperature up to 600F. It doesn't need secondary tempering temperature range because CWF HT doesn't has excess RA issue at low temperature, so it would be a lousy trade of strength & corrosion resistance & toughness for a tiny gain of wear resistance. When tempering, ideally I target for nano cementites and just enough ferrite for ductility.

Sorry language mistakes

Matti S.

Edited many times
Click to expand...
:thumbup: Thanks for your time and please post more...
 
Hello.
Thank you for not flattening me totally.
But I would like to argue at least one point. In my knowledge there is no clear limit to lover bainite (LB) hardness. When higher temperature LB will be softer and form faster until there will be higher bainite in-stead. Which is different and more like ferrite/cementite mixture. Lover bainite instead is much more like tempered martensite at same temperature, you even can temper LB less hard just like tempered marten-site. In fact metallurgy book, I read suggest (only theory and old book so maybe outdated information) that LB forms in fact by martensitic mechanism when austenite precipates carbon after time and be able to form slowly martensite at higher temperature (like diffusion controlled martensite reaction).
For pure LB maximum hardness 58 can be right, because in lover temperature there will be also marten-site. But even if there is partly martensite LB can be formed, only again harder and slower. But maybe process will be finally so slow that it do not matter, so I argue only for semantic. Then again in your heat treatment martensite formation is lesser while cooling, so there will be more austenite to form LB.
But whether there is LB or not, do not matter, because (I think) if martensite forms as stress free as LB (like you have managed) it should be as tough (if extrapolated same hardness).
While thinking response, I also realized, because in your heat treatment martensite transformation happens higher temperature, when steel is more pliable and diffusion easier, is possible, it do have more arranged and tougher lathe martensite, when traditional heat treatment it could have more brittle plate martensite.


Matti S.
 
Matti - my delight to read your advanced post :thumbup: and I agree with your conjectures on matrix transformation. I apologize if my points/statements inadventently construed/sounded like 'flattening', where they are intended as analytical attempts to garner a better metallurgical understanding. In this case, tracing backward from results to causes/reasons of what possibly/maybe/no-clue-statements taken place.

Below is my rambling thoughts, perhaps complement to your points + some...

It's true LB could occurs at temperature below Ms (martensite start). Ms is just a phase boundary where martensitic conversion becomes predominant, while LB occurs less and less as temperature goes lower. Alloy elements (by designed) serve as diffusion/activation barrier so which drastically reduce bainitic transformation rate over time. This bainitic tranformation time for these high alloy steels are usually in hours or days. There is a minute bainite transformation due to https://en.wikipedia.org/wiki/Uncertainty_principle, rate depends microstructure. This is a small component in aging transformation.

We often hear/read - duplex (tempered mart+LB, pick an exaggerated ratio - 60/40 per se) behaves similar to tempered martensite(80/20 mart/precip) when both have same HRC. In normal uses - sure, this is true however their microstructures are different (obviously). Bainite transformation (diffusion) occurs (mostly) where spatial favorable for aust to bainite (more or less precip). otoh, precip from tempering martensite favored/conducived by thermal+dislocation. Distribution of cementite & ferrite is one big different. The other one is duplex tempered mart most likely has bigger contigous mart clustered-unit-block then pure temperred mart. Sort have to be so because if duplex temperred mart structure+dimension is same as pure temperred mart, duplex would/must has lower hrc. Third duplex has higher ferrite%, therefore more ductile along with lower yield point (less flex before set).

FWIW conjecture/envisioning :D

CWF at quench and first 20 minutes, maybe LB (1-2%) may taken place. The rest of 2 stages transformation are aust to mart and ra to mart. Weaving is first stage, next cryo and activation is second stage. http://en.wikipedia.org/wiki/Breadth-first_search is another way to look at CWF concept. BFS animation http://en.wikipedia.org/wiki/Breadth-first_search#/media/File:Animated_BFS.gif <=> CWF stage1/breadth; stage2/recursive_baseline_nodes. Conceptually CWF is to build a skeleton/mesh/frame in stage1 and fill-in (ra to mart activation) in stage2.

Matti S. said:
Hello.
Thank you for not flattening me totally.
But I would like to argue at least one point. In my knowledge there is no clear limit to lover bainite (LB) hardness. When higher temperature LB will be softer and form faster until there will be higher bainite in-stead. Which is different and more like ferrite/cementite mixture. Lover bainite instead is much more like tempered martensite at same temperature, you even can temper LB less hard just like tempered marten-site. In fact metallurgy book, I read suggest (only theory and old book so maybe outdated information) that LB forms in fact by martensitic mechanism when austenite precipates carbon after time and be able to form slowly martensite at higher temperature (like diffusion controlled martensite reaction).
For pure LB maximum hardness 58 can be right, because in lover temperature there will be also marten-site. But even if there is partly martensite LB can be formed, only again harder and slower. But maybe process will be finally so slow that it do not matter, so I argue only for semantic. Then again in your heat treatment martensite formation is lesser while cooling, so there will be more austenite to form LB.
But whether there is LB or not, do not matter, because (I think) if martensite forms as stress free as LB (like you have managed) it should be as tough (if extrapolated same hardness).
While thinking response, I also realized, because in your heat treatment martensite transformation happens higher temperature, when steel is more pliable and diffusion easier, is possible, it do have more arranged and tougher lathe martensite, when traditional heat treatment it could have more brittle plate martensite.


Matti S.
Click to expand...
 
Hello.
What you write about LB is different than I have read in metallurgy book, but I had to admit that text is most likely simplified, because it do not explain some known difference in LB and martensite. No more about it.
What I asked before about traditional heat treatment, I did not mean secondary hardening (although now I understand that people likely to think that). I did mean hardness range 60-57 HRC in first (or only, whit simpler steels) hardening peak. Because in that area martensite softens but also precipitate sementite to grain boundaries. Which make toughness/hardness very nonlinear that area. If I have understood correct-ly what you mean by CWF, (small) problems in grain boundaries should not matter and you should get better toughness also that area and small changes in tempering temperatures that area should change toughness linear.


Matti S.
 
Tempering early precipitation (at low termperature) mostly taken place at interface boundaries. Interface potential energy corresponding to degree of dislocation. So grain boundary/interface is higher than between mart twin and carbides (6um and smaller). At this point (below 330F, 65-66rc), virtually precip w/o much diffusion (hence very little coarsening of cementite). Increase temperature until 58rc, interfaces are probably ferrite rich and cementite coarsened (in gb). I suspect (with limited visual confirmation) cementite coarsening is proportional to grain size. large grain (higher aust matrix energy) has higher dislocation, thus gb and neighbor are highly strained which take early precip, and then fast coarsening due to wider diffusion path. CWF aim/conceptual is to minimize a grain diameter growth and distortion against gb. However cwf doesn't refine grain, that step much taken prior to quench.

Toughness (in plasticity term) is indeed non-linear based on inhomogeneity within matrix. Of course that depend on scale of affected volume - e.g. may not discernible by something larger than the hardness tester indentor cone. Toughness (in impact load) also non-linear depend matrix able to absorp the load, which directly depends on matrix constituent distribution - e.g. ferrite & RA play big role.

Matti S. said:
Hello.
What you write about LB is different than I have read in metallurgy book, but I had to admit that text is most likely simplified, because it do not explain some known difference in LB and martensite. No more about it.
What I asked before about traditional heat treatment, I did not mean secondary hardening (although now I understand that people likely to think that). I did mean hardness range 60-57 HRC in first (or only, whit simpler steels) hardening peak. Because in that area martensite softens but also precipitate sementite to grain boundaries. Which make toughness/hardness very nonlinear that area. If I have understood correct-ly what you mean by CWF, (small) problems in grain boundaries should not matter and you should get better toughness also that area and small changes in tempering temperatures that area should change toughness linear.


Matti S.
Click to expand...
 
Sent a few reblades off to Luong so I can test 'em out.. super excited about this. Rebladed my xm18 in 10v and it's sitting at 68.5rc, just finished it up today!

Also did a blade in M4 and AEB-L for fun, but wanted to get this one done asap.

I'll keep you posted here on how it goes Luong!

i-pHwCzHB-X2.jpg

i-J3CNFWC-X2.jpg
i-jj4xQGx-X2.jpg

i-MLMXCwL-X2.jpg


i-vPrPw8g-X2.jpg
 
Woah, Josh ... are you CNC'ing those blanks prior to grinding the bevels?

Also, grinding was all done post-HT?

And in any case, AWESOME! I am very glad to read that you are giving this a run. Thank you :thumbup:
 
chiral.grolim said:
Woah, Josh ... are you CNC'ing those blanks prior to grinding the bevels?

Also, grinding was all done post-HT?

And in any case, AWESOME! I am very glad to read that you are giving this a run. Thank you :thumbup:
Click to expand...

No cnc involved dude... I don't even have a mill (yet) LOL

These were drilled out on a drill press, roughed in and ground prior to ht, sent for ht, then I did the final grinding and tuning (grinding the lock face and drilling the detent hole) after.

Thanks man, super stoked about this!
 
Josh - wow stunning rebladed job! You pre-ht ground those blades with high skills, so ht them were drama-free for me. From pic, look like you gave that 10V a super thin (behind edge ~0.010 +-0.002")? It sure looks wicked nice in xm18 frame.
 
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