Super quenched 52100 knife

BluntCut MetalWorks

BluntCut MetalWorks

Knifemaker / Craftsman / Service Provider
Joined
Apr 28, 2012
Messages
3,462
Greeting tinkerers!

My metallurgy R&D (aka tinker/hack) delivered knives which I consider high performance and well balanced for normal and hard uses. While retained ease-of-sharpening.

Blade: 52100 (ball bearing), 2mm thick, 92mm length, 24mm wide/tall
Digital controlled 1485F aust temp.
Super Quenched(SQ): brine + dish detergent (dawn) + surfactant (jet-dry).

SQ is not supposed to be possible for steel with carbon mass greater than 0.4%; 52100 has about 1.0%. Crack 'ping' is almost guarantee for those have tried whenever steel has more than 0.4%C.

Here is a link to my thread about SQ - http://www.bladeforums.com/forums/s...per-Quenchant-Speed?highlight=super+quenchant

Thanks for watching and comments.

[video=youtube_share;nlxw02FgBlA]http://youtu.be/nlxw02FgBlA[/video]
 
Thanks Fred!

A step up in challenge is D2, it's way more tricky to super quench but the reward will be greater in wear resistance ( 0.9% V + 0.8% Mo). Grain & carbide need to be very fine, otherwise ease-of-sharpening will degrade.

To successfully super quench any steel with excess 0.4%C (D2 has 1.5%C) is analogous to human sprints 100 meters in 3 seconds. This mumbo jumbo is meaningless (due to complicated unnecessary ht procedure)... unless the end product is clearly superior.

OK, is this something you guys curious about or just too far remove from sharpening & mod? To me it's relevant to sharpening because steel structure & carbide distribution directly affect the outcome of sharpening: burr amt, edge stability, durability and sustain cutting angle + behind the edge thickness.
 
Gotta download and watch! Congrats (blindly) to the success! :D

Edit to add: watched & like it ! :thumbup:
 
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Thanks Chris & Martin/HH!

Just occurred to me from super quench high temperature gradient, it seems possible to zone hardening - aka harmon. Although 52100 is not a shallow hardening like 1095/W2/etc., nevertheless I will try to clayless-harmon a 52100 knife :confused: :very_drunk:
 
Keep me on the short list for seconds, cosmetic blems, early test pieces you don't have the heart to scrap....;)
 
Conservative calculation - this latest experimental 52100 ht with super quenched.

  1. at least 50% increase in wear resistance.
  2. finer grain, guestimate sub 250nm.
  3. stronger microstructure.
Performance improvement projected to ~2x for cardboard & soft materials cutting and ~3x for hard materials. Hopefully I am not delusional thinking outloud:disturbed: Or I merely improved upon previous lousily made 52100 knives :rolleyes:

When time & resource PERMITS. I plan to apply my ht procedure to W1; W2; CruV; 1095; O1, I expect to get similar performance gain over the current known triple thermals grain refinement ht.

Having said all this, I don't have a baseline 52100 knife to compare with. I tried informal test relative-compared with production knives in steels: vg-10, zdp189, s30v, sg2, skd11/d2, blue#1, AS and other knives I made with various low & high alloy steels using mfg recommended optimal ht.

3rd person: Hey everybody, there got to be a lot of leaky holes in BluntCut's stuff -> quench him
 
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I still have the 52100 paring from same batch as 12 steel test. It has spoilt me in term of shaving. I can't imagine how I could go along before that :confused:

So you don't have the older 52100 you made last time, or simply you don't have factory 52100 to compare with?

If this one is estimated 2-3x better in wear resistance wow!... :eek:
 
For each significant experiment 52100 ht I kept at least 1 best knife as stepping stone comparison. Yes, I was referring to production or other's Knife Marker's 52100 knives to use as external baseline. I was going to send 2 knives to Peters Heat Treating Services but decided to delay that in favor of apply my ht to other steels mentioned above. Eventually I will send knives with various steels to Peters Ht.

2-3x performance improvement = additional amount of work can get done. While pure wear resistance only improved 50+% over previous test knife (in cardboard cutting video).

Chris "Anagarika";13494477 said:
I still have the 52100 paring from same batch as 12 steel test. It has spoilt me in term of shaving. I can't imagine how I could go along before that :confused:

So you don't have the older 52100 you made last time, or simply you don't have factory 52100 to compare with?

If this one is estimated 2-3x better in wear resistance wow!... :eek:
Click to expand...
 
52100 clayless harmon with super quench - FAILED!.

1st try with complete submerge (true harmon instead of just a quench line). The harmon is very diffused over almost 1 inch - hardly regcognizable. Failed.

Into the oven for 2nd attempt
2nd try with edge-quench, while a blow torch blow on the un-submerge part. Too sharp of a quench line, multiple deep vertical edge cracks.

Grind off the edge cracks and into the oven
3rd try with only edge quench, huge crack along the harden band - see pic
failed harmon.jpg

I super quench three 52100 knives, decided to video the last knife. Yeah I didn't feel like agitating the blade early, so the delay collapse was longer than what I want but no need for me to redo since quench was plenty fast.
[video=youtube_share;umEUb3Bp7_c]http://youtu.be/umEUb3Bp7_c[/video]
 
How are you estimating the grain size? If your estimate is accurate you are approaching the size of the Friction Forgrd D2 blades from Diamond Blade. That's 0.25 microns right? What are you doing to the blades before quenching? Forging, normalizing, etc.
 
I triangulate grain size by combined various vectors: stable edge at sub 10* inclusive angle; smallest burr pivoting (bend back/forth); sharpness from a rolled edge; compare to Opinel carbone+zdp-189+v2+1084 by sharpness & feel. Note: with super fine grain however thanks to Mn to keep pearlite nose gap about the same. Edit: yes, sub 0.25um grain size.

I did tried forging heat but found more pain than gain - with 9 seconds (super quench = ping music), it's still too brittle even temper at 550F. Performance is better than std ht but I wanted more.

I always normalize & sometime sub-critical anneal before ht thermal cycle. My pre-quench cycle is time consuming. And for D2 and other high Cr (excess of CrC) steels are challenging to manipulate metallurgical transformation phrases.

edit 2: DiamondBlade friction forge
After re-looked at pcbn friction approach. imho & wag: with Carbon-burning-heat+correct time in the aust-only phrase, V & Si can serves as grain refiner and balanced-Carbon after MoC & VC around 0.6, then matrix should be harden like simple carbon (65-67rc and possibly a 1 or 2 rc extra from VC & MoC if carbide size is large). Then don't temper above 500F to avoid CrC precipitation (LOL - they mentioned Cr added, rather it's just not carbide forming). I would hate to lose 1/4" of expensive hardened edge.
 
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bluntcut said:
I triangulate grain size by combined various vectors: stable edge at sub 10* inclusive angle; smallest burr pivoting (bend back/forth); sharpness from a rolled edge; compare to Opinel carbone+zdp-189+v2+1084 by sharpness & feel. Note: with super fine grain however thanks to Mn to keep pearlite nose gap about the same. Edit: yes, sub 0.25um grain size.
Click to expand...

I don't think that's how it works. Do you have a procedure for measuring grain size that way which shows it's accurate? That's right off the ASTM grain size scale, about 1/10 the size of a 14.
 
I am NOT at a stage where I would send a sample to be nano-polish then etch for some sort of EM scan. In the mean time, I will apply my ht procedure with other low Cr steels, where grain size can be interpolate and or extrapolate. Super fine grain is 1 of few required criterias for a successful super quench(SQ). SQ possibly created excessively sheared elongated martensite, grain boundary limit such elongation but a the same time large grain also limit ductility, whereby crack ensure if martensite actually crack the grain. Dimensional changes and lattice holes will tear the matrix up (aka ping/crack).

me2 said:
I don't think that's how it works. Do you have a procedure for measuring grain size that way which shows it's accurate? That's right off the ASTM grain size scale, about 1/10 the size of a 14.
Click to expand...
 
bluntcut said:
I am NOT at a stage where I would send a sample to be nano-polish then etch for some sort of EM scan. In the mean time, I will apply my ht procedure with other low Cr steels, where grain size can be interpolate and or extrapolate. Super fine grain is 1 of few required criterias for a successful super quench(SQ). SQ possibly created excessively sheared elongated martensite, grain boundary limit such elongation but a the same time large grain also limit ductility, whereby crack ensure if martensite actually crack the grain. Dimensional changes and lattice holes will tear the matrix up (aka ping/crack).
Click to expand...

No, I don't think it's time to send one out for that yet either. Optical microscopy is considerably less expensive though. Why do you think the low Cr steels allow for grain size to be estimated the way you're using? Why do you think super quenching (extremely fast cooling rates) produces smaller than ultra-fine grain size? You are giving some extraordinary results using what appear to be very unusual and questionable methods that have never been mentioned here or any other blade making site I've read. I'm just taking things with a healthy dose of skepticism.
 
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