Heat Treatment - Crystal Weaving Foundation

Good guess from an experienced hter like yourself, Devin.

Grain size plays minor role in CWF. The video demo of 8670 knife above - I purposedly bloated its grain by aust around 1800F long soak; turned off heat; when temperature fall to around 1550F CWF it. No temper.

DevinT said:
My guess is that you are doing some grain refining before quenching from higher than normal aus temps, using shorter soak times to prevent grain growth.

Hoss
Click to expand...
 
Last edited:
:thumbup: my recommend CWF aust temp will be around 50F higher than mfg's max aust temp for most steels(except for a handful).
DevinT said:
Got the higher than normal aus temp right anyway.

Hoss
Click to expand...

edit to add: reason for higher aust because RA won't be an issue + finer carbide + more homogeneous elements distribution. But should avoid grain growth, unless some applications might benefit from larger grain.
 
Last edited:
Interesting stuff.

Appreciate the explanation for us regular folks. So that's the science behind the process.

Thought he was filling the gaps with crystals. Carbide crystals. D:
 
Here is my process to come up with conceptual/logical CWF 'how'. But 'how' to 'what'? So I must clearly/quantitatively define 'what' is the goal? otherwise - the whole process is like a blind squirrel looking for moon nuts - well: I contacted NASA, my chance increased by 10^-18 :p

Graph

Map an aust volume (inside a grain) as volume/3D graph, where Fe & C are vertices and inter-atomic electromagnetic as edges. FCC = planar Fe4C = 5 vert 4 edges. There are total of N edges.

FCC transformation to BCT, where BCT = volumetric 9 vert 8 edges.

Optimization Goal:
1. optimize for highest number of edges from 1N to 2N (can't get to 2N because of volume skin/outer surface). Strength & toughness components.
2. least increase in volume radius. This is spatial/dimension component, which affect inter-grain.

Since BCT transformation is shear volume (i.e. increase length in one direction, hence orientation), easy to see/simulate an optimal volume graph should be where BCT change orientation(weave) at smallest cell unit as possible minimal # of broken/disconnected edges.

Well, I expect a few of you to turn ON those LN2 cool super-cluster-massive-parallel computer to crunch this graph. I would like 10 best configurations. Maybe throw in hexagonal and cementite as well.

*** GOT IT - said you :cool: ***

Physical/practical/applied ht-CWF 'how' with step-by-step to be disclose.
 
Last edited:
Probably the most interesting thread I've read on BF in a long time. Interested to see what comes of this!
 
Physical/practical/applied ht-CWF 'how' with step-by-step to be disclose.
Click to expand...

This is the part I'm looking forward to with great anticipation! Please share when you're ready.

I'm sure Liquid Nitrogen will be important, but please don't forget us using Dry Ice.

Ken H>
 
Low temperature is more/less using thermal contraction (reducing atomic radius). So whether DI sufficient to de-active crystal (reduce collective atomic radius) is to be try/test. Maybe a freezer temp would be ok too :)

...

Ken H> said:
This is the part I'm looking forward to with great anticipation! Please share when you're ready.

I'm sure Liquid Nitrogen will be important, but please don't forget us using Dry Ice.

Ken H>
Click to expand...

Certainly. If something is too complicated & convoluted, maybe it's just a deception or someone trying hard to sound smart :p (doh, did I typed that!)

tinfoil hat timmy said:
I'm soooooooooooooo lost. ;) We lay man can still watch right?
Click to expand...
 
Last edited:
tinfoil hat timmy said:
I'm soooooooooooooo lost. ;) We lay man can still watch right?
Click to expand...
bluntcut said:
edit to add: if foresight is short, just wait for hindsight. No need to back stab LOL:thumbdn:
Click to expand...

I hope you didn't take this as an insult or slight because it doesn't seem to be stated as such.
--------
I have not checked in on this topic for the last few days, and I am trying to get caught up, but it is starting to get rather rich in technical info that I am not that well versed in...

I have been doing some thinking about this topic and I am curious if the higher Aus temp with a controlled cooling prior to quench has some effect...

Trying to get certain phases (or one phase dialed in) to "line up" and a quench when the alloy reaches a certain temp to lock it all down in as close to a purely banetic existence as possible?
Or at least trying to take advantage of bainite not needing the tempering that martensite needs or the lack of hardness that pearlite can offer.
 
Last edited:
resolved...

--------

A few hters had similar good guesses but bainitic represents a lot of disconnected edges (resulted in further down from 2N) in the BCT graph hence loosing strength (nano matrix strength - free of particles/carbides).
I have been doing some thinking about this topic and I am curious if the higher Aus temp with a controlled cooling prior to quench has some effect...

Trying to get certain phases (or one phase dialed in) to "line up" and a quench when the alloy reaches a certain temp to lock it all down in as close to a purely banetic existence as possible?
Click to expand...
 
Last edited:
Hrm, I was thinking upper bainite with martensite smaller than 10um to try to limit fracturing?
 
upper bainite ~250nm spacing sheaves are just soft/ferritic & hard fingers/needles/cementite, thereby ductitle/weak & brittle at the same time.
NJBillK said:
Hrm, I was thinking upper bainite with martensite smaller than 10um to try to limit fracturing?
Click to expand...
 
Could what in have been reading have been aimed at low carbon alloys?

Below is what I was referencing:
-The Microstructure of Continuously Cooled
Tough Bainitic Steels
1 F.G. Caballero, 1 C. Capdevila, 1 J. Chao, 1 J. Cornide and 1 C. Garcia-Mateo,
2 H. Roelofs, 2 St. Hasler and 2 G. Mastrogiacomo
----------
I Really would love to have a firmer grasp of the technical aspects of how materials "work"...
This topic has me absolutely enthralled and searching for everything in can find to try to get a handle on this and be able to understand how it all works at a Much smaller scale than I am used to thinking on.
 
Last edited:
UTS for bainitic steels is below max 1500 MPa. While pedestrian fully martensitic steels easy surpass 1700MPa.

Bainitic - beside low strength, lacked of weldability limits its application in larger structures.

Edit: um... did you say something about not well-versed? Deep stuff you threw at me :thumbup:

NJBillK said:
Could what in have been reading have been aimed at low carbon alloys?

Below is what I was referencing:
-The Microstructure of Continuously Cooled
Tough Bainitic Steels
1 F.G. Caballero, 1 C. Capdevila, 1 J. Chao, 1 J. Cornide and 1 C. Garcia-Mateo,
2 H. Roelofs, 2 St. Hasler and 2 G. Mastrogiacomo
Click to expand...
 
Noticed that I edited as you were posting.
I will be doing some more thinking and trying tosee what i can source.

Thanks again, I love (and hate :D ) this stuff!
 
bluntcut said:
:thumbup: my recommend CWF aust temp will be around 50F higher than mfg's max aust temp for most steels(except for a handful).
Click to expand...

Mind if I ask what steels you would not suggest this for?
------
bluntcut said:
Edit: um... did you say something about not well-versed? Deep stuff you threw at me :thumbup:
Click to expand...
Thanks!
I am just a dumb guy trying to act smart.
At least that is how it feels...
 
You must log in or register to reply here.
Back
Top