Heat Treatment - Crystal Weaving Foundation

[Cobalt]

Happy new year.

The Carothers was 18 dps and the busse was 15 dps. The blades were both small so the damage looked bigger than it really was. Neither failed. Both dented and resisted fracture. The numbers are somewhere in another thread. I hammered on both between 6 and 7 minutes total each.

 

[BluntCut MetalWorks]

Per request ...

Cutting 1/2" dia sisal rope - stop when edge no longer cut phone book paper or a few thousands cuts.

CPM T15, 65rc HT 3.0, ~15dps, ~ 0.0055" behind edge thick

Edge after 4K cuts and still decently cut phone book paper

Video 15m44s

Will ht 3.0 these little blades later this week:

 

[BluntCut MetalWorks]

This test-batch#3 of heat treatment 3.0 took ~30 hrs. All/together blades were austenited at 1990F, soak 30-45minutes. I am stoked.

Test Objective: Collect data for edge damage/failure mode, specifically deformation vs fracture/chip. *edge geometry will be varying among test blades.

Steels:
440C ESR 63rc, 18dps
Niolox 62rc, 18dps
3V 63rc, 18dps
S30V 64rc, 17dps
Zwear 64.5rc, 15dps
10V 66.5rc, 17dps
NitroV 61.5rc, 19dps
N690 62.5rc, 18dps
CPM 154 64rc, 18dps
Aebl 61.5rc, 17dps

Tests:
Whittle raw pork rib bone
Baton 5D nail

Result

video 15m23s

 

[BluntCut MetalWorks]

Just finished another set of ht 3.0 test blades [D2, 1095, cruforgev, w2, 52100]. HT 3.0 process took over 40 hrs to complete. And expect future ht to take longer and longer until diminishing perf gain or die in shock seeing the electricity and LN2 bills.

Result working/testing hardness: D2 66 & 65.5rc, 1095 66rc, W2 65.5rc, 52100 64.5rc, cruforgev no hrc reading yet.

I plan to conduct simple test for this batch using edge geometry: 15 dps, ~0.012" behind edge thickness. Each cut 5D nail 3 times.

To make this test video fun, I will test D2 65.5rc HT 3.0 against Vanadis 4E 64rc HT 2.5. *see previous page for vanadis4e 64rc tests. This V4E knife is from 2 0f 3 set.

Oh heck, Let's toss 1095 66rc into this match as well.

Winning odd among these 3 steels?

My projection on outcome: 1st 1095, 2nd D2, last V4E.

 

[BluntCut MetalWorks]

~ 15 dps

Blades in this batch. 50 grit grind in progress...

Edit Jan15:

This batch of blades - found spotty temperature issues, lead to lowering hrc via temper, which doesn't works as well as targeted hrc. W2 & D2 lowered to 65rc. The long D2 blade is unwieldy, to be shorten to 7". Destructed test a w2 blade.

50 grit ground bevels were below 0.025" = too thin for rough grinding impact, some crumbled edges, need to remove weakened edges and thin with 120 grit belt.

Ordered a Paragon ht oven (24" depth). It should supports better temperature resolution and precision.

Still, I will make nail cut test video. * v4e and d2 will have edge thickness around 0.015" rather than 0.012" stated above. 0.012" is just too thin for part time chopping blades. At same dps, thickness behind edge isn't a factor when nail cutting damage is less than 3/4 of the sharpening bevel.

Common D2 often has carbide banding and cluster of large diameter carbides, so plastic deformation is limited by displacement until pile-up. Flex/deflection range also reduced. D2 in this batch should performs fine in most tests, except bulk (large macro) deformation and lateral flexing.

About W2, 52100, cfv, 1095 - these are old blades prepared for pre-cwf 1.0 ht. 1095 was newest among them. In a prelim nail test, 1095 beats w2 and 52100 and about same as cfv. My new super quench tank only has 1/3 amount of dish detergent and extra surfactant/jetdry = need a few round before adjusting to its cooling rate. I cut 2 full tang blanks each steel: 1084, 1095, cfv, w2, 52100, O1 for future batch of carbon test set.

Inquired about 15V. Want to test 3+%C and no Co% steels.

Still deciding on next batch of ht 3.0 - candidates:
A. I've a bar of 10V which fits for 2 decent partial tang choppers. Target 67rc
B. M4 small and S690 mid size. Target 65rc
C. T15 hunter. Target 68rc
D. Niolox, Aebl, NitroV. Target 65rc

 

[BluntCut MetalWorks]

Cutting can, 5d+some 6d nail tests. All blades sharpened to 15dps

Vanadis 4E 64rc HT 2.5 - as baseline. 0.015" BET

Below blades s are HT 3.0
D2 65rc 0.015" BET
CruforgeV 64rc 0.015" BET
W2 65rc 0.013" BET
52100 64.5rc 0.013" BET
1095 66.5rc 0.012" BET

I ranked them at close-visual:

video 23:41

===========
Leaning toward doing s30v, niolox, .. next.

Edit Jan16:
Next/niolox&Co batch will includes 4 odd guests: 52100, O1, W2, 1095. Guest's grain size will be humongous. Target 65 - 67rc. Yup, need to break (huge grain) something then fix with new weave...

Maybe will do some arm & wrist exercise by cutting some sisal rope with D2 65rc (using 2" edge section), will see how it lasts before stop slicing phonebook paper. Just found 3 long dirty/sandy lobster buoy rope. Well, it won't take long to dull any knife.

Ordered cts204p & psf27 steels. will queue a batch of 204p+m390+elmax+s90v+20cv.

Look like I will get some 15v too. Maybe will group this one into T15 batch.

** cutting dirty 3/8" dia polypropylene rope **
initial edge: slice phonebook. stop edge: can't cut with 25+lbs press down force
- same 12" section of rope
D6 65rc ht 3.0 - 35 cuts
Vanadis 4E 64rc ht 2.5 - 23 cuts

I found this at beach walk today - storms washed them ashore.

edit Jan 22nd:
niolox, s30v,.. batch didn't worked well using a new faster ht time (30 hrs). Well, at least 3v/65rc and 440c/63.5rc turned out very well. S35vn/64rc is just above std average. Niolox/64 is similar to ht 2.5. Aebl/64rc is below average. NitroV/63rc is poor. Didn't/won't test s30v/64rc.

Carbon blades (w2,1095,O1,52100) were good - grain size is larger than projected, around 200-250 microns. Successful in term of able to achieved micro intragrainular fracture; however due to delayed time from removing the foil, grain boundary was deposited with too much diffusion, thereby can't fix macro intergrainular fracture. Nail chopping 3d,5d,6d shown erratic plastic deformation and brittle phase. O1 blade exploded into pieces when hammer hard trying to chop a 16D nail.

Later on, will re-ht most blades from this batch, using slower ht time.

When 15v arrive, will ht a batch of T15, M2 and 15V.

Edit Jan 25th:

Not enough LN2 in dewar and 15v isn't arrive for a few more days so went ahead with
ht 3.0 34hrs: M2 66+rc, T15 68rc. Removed 1 step and added 1 step to ht.

psf27 and 204p steels arrived yesterday. Cut 4 psf27 blanks. Later, will ht a batch of 4x psf27 and a D2 blades.

10v and s90v steels shipment was delayed but on their way now.

Additional 30L dewar ETA Monday. Will fill 2 dewars (50L total) Tuesday or Wednesday.

 

[BluntCut MetalWorks]

Cutting sandy/dirty plastic/polypropylene 0.4" diameter rope. Each blade cut end when it is no longer cut under heavy pressure.

Spyderco manbug ZDP 189 - baseline
Vanadis 4E 64rc HT 2.5 - baseline

Below are HT 3.0
3V 64.5rc, 440C 63.5rc, Cfv 64rc, D2 65rc, M2 66rc, Niolox 64.5rc, S30v 64rc, CPM T15 68rc.

Result:

Video 17m14s:

Edit Jan 28:
I have another 63rc 3v blade with ht 3.0 in previous ht batch. It made 28 cuts through the remain of the 2 test rope sections. *note: the 2nd rope section is a little bit less sand than other blades subjected to because I shook some sand off it near the end of the video.

Received cpm 15v sheet ht#np66255, composition: 3.5%C, 0.91%Si, 0.014%S, 0.4%Mn, 5.25%Cr, 1.26%Mo, 0.024%P, 14.86%V.

Edit Jan 30:
Received 10v and s90v shipment.
In progress ht 3.0 batch 4x 15V and 1x M4 blades, aust 2150F with target hrc 69 and 66+ respectively.
Preparing next 2 batches: [cts 204p/m390, s90v, 10v, s690], [psf27, d2]

 

[Chris "Anagarika"]

Luong,

There’s one small hole near the tang of the trailing point (hunter?) that may become stress riser. I know your HT is special, but maybe it’s better not having the hole?

Below is likely bad HT butthe stress riser is the hole.
https://www.bladeforums.com/threads/crkt-sangrador-fail.1621065/

 

[BluntCut MetalWorks]

Chris,
Is this s30v drop pointer hunter - here is a close up on the first pin hole (slightly clean up tang).

?
Maybe it was just bad light. There is a fairly sharp angle sharpening notch transition between edge and guard which could somewhat a stress riser if not rounded (hasn't round it yet with diamond file).

In general though, first/front pin hole area is usually weakest point on the tang. Plunge line is another weak area - note: best plunge line should has some curvature, vs. my is whatever my belt decide to munch/grind, yeah messy cut actually yield some curvature (win win eh!).

Luong,

There’s one small hole near the tang of the trailing point (hunter?) that may become stress riser. I know your HT is special, but maybe it’s better not having the hole?

Below is likely bad HT butthe stress riser is the hole.
https://www.bladeforums.com/threads/crkt-sangrador-fail.1621065/

 

[Chris "Anagarika"]

Luong, it’s the top knife displayed on the YT link you posted. Are those the same? Haven’t chanced watchingthe video(s) but that hole caught my eyes.

Of course it’s not designed as throwing knife but BCMW are famous for being tough while maintaining high hardness some people might be tempted to try.

 

[BluntCut MetalWorks]

Yup, close up pic is the top knife in video frame.

Luong, it’s the top knife displayed on the YT link you posted. Are those the same? Haven’t chanced watchingthe video(s) but that hole caught my eyes.

Of course it’s not designed as throwing knife but BCMW are famous for being tough while maintaining high hardness some people might be tempted to try.

Updates:

Cut 3d, 5d and 6d nail with T15 and M2. 66rc M2 did too well (no chips, thus reasonable to doubt), so will put edge on the 2nd M2 blade for same test. T15 did well with localize chips - about 10% larger than rolled magnitude on M2 edge.

From result above, I mid-stream retargeted hrc 15V and M4 to 67 and 65. Plus adding 2 extra steps to ht sequence. Put 150 ceramic grit edge on 15v and m4, probably around 13dps... will use EP with 400 & 600 diamond plate on these 2. to be test soon.

Cut 16 blade carbon steels [w2, 52100, 1095, O1] - amassing to 24 blades total, plus w2 and 52100 strip for bend test. Will add 6x w2 and 6x 52100 test coupons - reserve option for charpy and metallurgical analysis.

15v 67rc edge 15dps 1000 grit diamond plate: passed whittle and cut cooked dried pork rib bone. barely visible micro-chips (hesitate slice phonebook paper) whittle cooked dried cow femur bone.

m4 65rc edge 15dps 1000 grit diamond plate: passed whittle and cut cooked dried pork rib bone. micro ripple almost not visible (still slice phonebook paper) whittle cooked dried cow femur bone. Max depth of ripples is about 70% compare to 15v micro chips.

 

[BluntCut MetalWorks]

Rough summary for: 65rc M4 behaves almost similar to 66rc M2 + 68rc T15 localized (radial from contact point) chip + 67rc 15V micro chips (and some deformation sub 50um range) + previous test sets result

HT 3.0 produces stable matrix microstructure around 65rc at ~10% carbide volume(CV), 64rc ~15% CV. For high impact load, lower hardness by 2-3hrc.

Keep in mind: 18dps has 73% more volumetric strength than 15dps. vs = (18/15)^3.

My vision of an ideal ht 3.0 matrix, which should composed from 85-90% martensite, 10-15% hcp. This outcome is highly dependent on martensite nano subgrain block. With 2nd oven and 2nd dewar, hopefully I can produce result, which shows definitive hcp% present in matrix (cross into double digit%). 65-66rc W2 & 52100 bend test should provide hints when to proceed with SEM or even TEM for visual confirmation of subgrain block (need atomic force microscope to visualize hcp).

Edit Feb 2nd:
Forgot to mention - burr removal is harder now due to tougher matrix. Last night, I've a tough deburring time with 15v, t15, m4, m2 blades using 3 diamond plates. At 2K sharp finish grit, burrs stop side-to-side flop after 3-4 times. I did tried gentle fold and cut burr removal method - worked for big burrs (maybe over 5um) but smaller burrs hung on. M2 got sharpest but prolong cross grain newsprint cut required additional deburr - i.e. apex isn't burrs/wire-edge free... remind me, burring of Spyderco knives in vg-10.

Edit Feb 8:
4x M2 66rc blades behaved consistently tough at this hardness, hence more comfortable in removing some doubts. however need to repeat without pre-ht grind to eliminate thin cross section(edge) possibility of thermal issues. Well, I've 4 nifty good M2 blades all nicely ground.

Still have quite a bit of belts but plan to grind a lot, so ordered total 150 ceramic belts in 36,50,80,120 grits.

3x T15 68rc blades are ground, 1.8 of 4 15v are ground. T15 somehow quite pleasant to grind, especially with fresh 50 grit ceramic belt.

Praxair is out of LN2 until next week. Too bad but not bad, since new order of steels for test bending coupon will be here and to be prepare in large number.

Maybe will pre-harden-ht prep a bunch of carbon blanks and coupons this weekend.

** calling @jpm2 - if you like to play/have a m2 66rc 0.088" thick, 3.4" edge, partial tang blade and put handle on yourself - lmk.

Edit Feb 9:
Paragon ht oven scheduled for delivery on Monday - yay! I need to pull a new 220V 20A line for it.

 

[BluntCut MetalWorks]

 

[BluntCut MetalWorks]

HT 3.0 D2 and PSF27. Both tested (off camera) with similar performance, D2 at 63.5rc and 64.5rc, psf27 63rc and 64rc. Picked psf27 for this video, since these psf37 blades are my first time dealing with this steel.

Objective is to find out edge failure mode when encounter hard + uneven rupture material = bone.

Here is close up of edge after test = ripples along the edge

Video: 4m24s

 

[BluntCut MetalWorks]

For comparison of edge cutting 6D common nail. I found the 52100 64.5rc blade as tested 1/15/2019 however vanadis 4e 64rc ht 2.5 edge been fixed. I am excited with the latest D2 result, definitely will repeat the experiment a few times with same and minor deviations of ht parameters - if there are unknown/don't-know-what-don't-know errors, hopefully this process will show them. D2 result is looking very good in compare to 52100 and vanadis 4e.

Anyway stitched old and new images:

Edit Feb 12th:
Received Paragon Double Barrel 24" HT oven yesterday. Tested fire up to 300F fine. Too bad, no time to use it until this weekend.

 

[BluntCut MetalWorks]

The new ht oven (Paragon Double Barrel 24D) has wider temperature fluctuation at sub 500F range than Evenheat oven: 50+F vs 25+F ramp 180-300. Once oven temp is stabilized, ramp 120 is very good for both oven. New oven solid state relay is quiet compare to evenheat analog relay with loud clicks. Still need to pull a new 220v line to have both oven run at the same time.

Bought only 20L of LN2 last Friday. Praxair 2019 LN2 pricing is close to gouging level $7 per liter. Next purchase will be 50L LN2 at AirGas 40 miles away.

Re-profile a D2 chopper blank for Feb 16th ht batch. Tested NC(not complete all ht 3 sequences, of course untempered) 65rc D2 & PSF27. Result show micro roll/ripple, macro chip. D2 15 and 18 dps chopped 2x4, oak, eucalyptus = passed but I doubt its durability. Both blades are going through the rest of ht sequence then will updates this post with additional tests result. Aim for final hrc about 63.5-64.5

Upcoming ht batches: s90v, 10v, simple carbon. bending tests will be 95% on simple carbon coupon.

If all progressed well, visual verification will be done using combination of potential instruments [Scanning E, Back Scatter E Diff, Trans E, Atomic Force, Focused Ion]. Will snap pics of instruments IF lab allows.
.

 

[DeadboxHero]

The new ht oven (Paragon Double Barrel 24D) has wider temperature fluctuation at sub 500F range than Evenheat oven: 50+F vs 25+F ramp 180-300. Once oven temp is stabilized, ramp 120 is very good for both oven. New oven solid state relay is quiet compare to evenheat analog relay with loud clicks. Still need to pull a new 220v line to have both oven run at the same time.

Bought only 20L of LN2 last Friday. Praxair 2019 LN2 pricing is close to gouging level $7 per liter. Next purchase will be 50L LN2 at AirGas 40 miles away.

Re-profile a D2 chopper blank for Feb 16th ht batch. Tested NC(not complete all ht 3 sequences, of course untempered) 65rc D2 & PSF27. Result show micro roll/ripple, macro chip. D2 15 and 18 dps chopped 2x4, oak, eucalyptus = passed but I doubt its durability. Both blades are going through the rest of ht sequence then will updates this post with additional tests result. Aim for final hrc about 63.5-64.5

Upcoming ht batches: s90v, 10v, simple carbon. bending tests will be 95% on simple carbon coupon.

If all progressed well, visual verification will be done using combination of potential instruments [Scanning E, Back Scatter E Diff, Trans E, Atomic Force, Focused Ion]. Will snap pics of instruments IF lab allows.
.

Congrats on the new furnace, very nice.
Yes that's a horrible price on LN. I get $2 per liter here at airgas.
Look forward to seeing more with PSF27.

Hope there is more T15 testing too.

 

[BluntCut MetalWorks]

AirGas in Ventura charges around $3/L for LN2, factoring in truck and fuel, it should come around $4/L. When at Praxair, I saw they charged a customer $27 for 2L of LN2 - ouch!

Comparing D2 vs PSF27 to now with ht 3 - I didn't find differences big enough to measure.

After lab nanographs - I will do more test on T15, 15V, 10v chopper, etc.. So far, T15 68rc is very impressive in edge stability and performance tests. With latest ht params, will target 69+rc for T15 and 15V.

Congrats on the new furnace, very nice.
Yes that's a horrible price on LN. I get $2 per liter here at airgas.
Look forward to seeing more with PSF27.

Hope there is more T15 testing too.

Update 2/18 18:00
D2 64.5rc chopper, psf27 64rc they matched previous d2 and psf27 batch. I took 1 D2 from previous batch, applied few steps along with this batch - it is now 64rc (dropped 0.5rc).
Tested D2 chopper, included mild chops AB block = passed. Chops were full swing. Building up more confident in spite of thin edge and 64.5rc.
Will test cut 6D nail with psf27 blade later this eve.

 

[unwisefool]

I'm sure this has been answered before, but when do you say "ok, this is the heat treat, it's the bees knees, I have forged Excalibur, and this is ready for the public" and then what are the plans after that? Are you going to offer custom heat treats or submit it for peer reviews or something?

 

[Cobalt]

I'm sure this has been answered before, but when do you say "ok, this is the heat treat, it's the bees knees, I have forged Excalibur, and this is ready for the public" and then what are the plans after that? Are you going to offer custom heat treats or submit it for peer reviews or something?

There are people that have been playing with heat treatments for decades and they still find ways of making improvements. It's not as easy as it seems. The journey is more fun, in any case.