BluntCut MetalWorks
Knifemaker / Craftsman / Service Provider
- Joined
- Apr 28, 2012
- Messages
- 3,462
20180324 HT 2.5:
HRC at peak/highest and at 400F tempered:
A2 67, 64 https://www.alphaknifesupply.com/Pictures/Info/Steel/A2-TC.gif
Cruwear 67, 65 https://www.crucible.com/eselector/prodbyapp/tooldie/cruweart.html
RWL34 66, 65 http://www.damasteel.se/files/8414/5670/2913/flyer_rwl34_A4.pdf
Becut 63, 60.5 http://www.bestar-steel.com/wp-content/uploads/BECUT.pdf
440C 65, 63 https://www.alphaknifesupply.com/Pictures/Info/Steel/440C-TC.gif
W2 Chopper 67, 65
CruforgeV Chopper 66, 64 https://www.alphaknifesupply.com/Pictures/Info/Steel/CruForgeV-TC.gif
20180325 HT 2.5, HRC peak, 400F, 500F tempered:
S110V 66, 65
M2 67, 65
M4 69, 67, 65
* also at 500F 10V/65, 4V/64.5 and some M4 at 64-64.5rc, s690/65
20180326:
Tested Cfv & W2 choppers - edge failure mode = rolled, with repeated impacts (aluminum tubing) rolled eventually micro chips. W2 is probably 64rc rather 65rc from impact but could also because edge is a tad thinner than cfv.
Tested A2 64rc - passed whittled african blackwood, beef rib bone *with nano rolled, feel but can't see, verified with 22x loupe. chop beef rib bone(brb) = rolled -> ripple -> micro chips. A2 64rc performed very well. Will look into making chopper, especially it is much easier to grind than cfv.
Tested M4 67rc - pass whittled AB but micro-chips at brb. Chop brb = micro chips almost twice as large as A2. Will re-test M4 at 65rc.
Est W2 grain diameter is less than 1.5um (geez! accidental snapped tang while doing a dumb cold straightening). Grain refinement is faster & more effective now.
64-65rc edges seem excellent for high end user/usage which would supports impact & hard edc uses with edge geometry ~ edc: 15dps, 0.01"BET impact: 18dps, 0.02"BET.
20180327:
Heavily chopped & batoned hard woods with Cfv chopper - easy passed.
W2 chopper is 1/4" thick 10.5" blade but only 1.5" wide, so I distal taper to around 0.11" spine near tip. It's more like a knife toward the front with overall 15dps, 0.012-0.015" BET. Chop fairly deep into wood even though it lacked chopper momentum. Quite impressed how this thin edge withstand heavy chopping.
20180329:
After some triangulating my ht for many steels - there is some correlation between silicon excess of 0.4% lead to edge instability at high hrc. Si is an austenite stabilizer, so stabilized RA% is proportionally to poor keen edge holding, also mushiness (weakened) edge failure. Si% in many Crucible PM steels are unnecessary too high in 0.8-0.9% range, with cru-wear at 1.2%Si. Except for 10V & 15V extra high C% which would benefit from additional Si%.
Elmax 0.8%Si and M390/20cv 0.7%Si are the other 2 steels, which I mostly will avoid when ht for 64+rc working hardness.
20180330:
After some retrospective looks at sub micron edge holding/retention (fresh sharpen & sealed - hence remove corrosion factor) for various steels. I think, element volume% sum(Cobalt + Silicon) is proportionally tied matrix slip/yield at nano level. Which dictate matrix yield strength at sub micron level - translate to apex width degradation rate.
For 2-3 years now, I couldn't pinpoint why 52100 has better nano edge than W2 (both steels from NewJersey SteelBaron). Respectively, it is 0.07%Si vs 0.21%Si. Blue#2 has 0.16%Si, which seems to has good apex retention width between 0.7-1.0um very well. 52100 sub 0.5um, W2 1.0-2.0um. aebl 2.0-3.0um. niolox 0.5-1.5um. so on... depends on Co+Si element volume%.
Co localize affected matrix is around 45hrc. Si localize induced RA around mart unit & particle matrix is basically at ferrite level - 20 to 26hrc. For high Co% steels, such as maxamet 10%Co + 0.25%Si, sub 2um apex has higher yield strength than with 0.4%Si.
63-64rc overall matrix probably allow 0.2um thinner apex than sub 61rc.
65+rc overall matrix probably allow 0.3um thinner apex than sub 61rc.
^ both can't negate Co+Si affect. So 64-65rc is a good balance point of edge retention (given edge support intended load/usage).
So for good sub-micron edge shaping & holding, I will re-test njsb 52100, cruforgeV, blue#2, niolox. All assuming their CA Specs on Si% is correct. Niolox has good corrosion resistant due to 12.7%Cr however later on I need to further analyze whether Cr acts as a lattice slipper or blocker. At this point, Cr looks like a blocker, since fracture is common failure mode Cr rich matrix.
Other elements on the same periodic table line as Si are most likely be as bad but I ignored them because most steels are relatively clean. Of course, when sum mass% getting past 0.05% - time to pay attention and perhaps avoid such steels.
HRC at peak/highest and at 400F tempered:
A2 67, 64 https://www.alphaknifesupply.com/Pictures/Info/Steel/A2-TC.gif
Cruwear 67, 65 https://www.crucible.com/eselector/prodbyapp/tooldie/cruweart.html
RWL34 66, 65 http://www.damasteel.se/files/8414/5670/2913/flyer_rwl34_A4.pdf
Becut 63, 60.5 http://www.bestar-steel.com/wp-content/uploads/BECUT.pdf
440C 65, 63 https://www.alphaknifesupply.com/Pictures/Info/Steel/440C-TC.gif
W2 Chopper 67, 65
CruforgeV Chopper 66, 64 https://www.alphaknifesupply.com/Pictures/Info/Steel/CruForgeV-TC.gif
20180325 HT 2.5, HRC peak, 400F, 500F tempered:
S110V 66, 65
M2 67, 65
M4 69, 67, 65
* also at 500F 10V/65, 4V/64.5 and some M4 at 64-64.5rc, s690/65
20180326:
Tested Cfv & W2 choppers - edge failure mode = rolled, with repeated impacts (aluminum tubing) rolled eventually micro chips. W2 is probably 64rc rather 65rc from impact but could also because edge is a tad thinner than cfv.
Tested A2 64rc - passed whittled african blackwood, beef rib bone *with nano rolled, feel but can't see, verified with 22x loupe. chop beef rib bone(brb) = rolled -> ripple -> micro chips. A2 64rc performed very well. Will look into making chopper, especially it is much easier to grind than cfv.
Tested M4 67rc - pass whittled AB but micro-chips at brb. Chop brb = micro chips almost twice as large as A2. Will re-test M4 at 65rc.
Est W2 grain diameter is less than 1.5um (geez! accidental snapped tang while doing a dumb cold straightening). Grain refinement is faster & more effective now.
64-65rc edges seem excellent for high end user/usage which would supports impact & hard edc uses with edge geometry ~ edc: 15dps, 0.01"BET impact: 18dps, 0.02"BET.
20180327:
Heavily chopped & batoned hard woods with Cfv chopper - easy passed.
W2 chopper is 1/4" thick 10.5" blade but only 1.5" wide, so I distal taper to around 0.11" spine near tip. It's more like a knife toward the front with overall 15dps, 0.012-0.015" BET. Chop fairly deep into wood even though it lacked chopper momentum. Quite impressed how this thin edge withstand heavy chopping.
20180329:
After some triangulating my ht for many steels - there is some correlation between silicon excess of 0.4% lead to edge instability at high hrc. Si is an austenite stabilizer, so stabilized RA% is proportionally to poor keen edge holding, also mushiness (weakened) edge failure. Si% in many Crucible PM steels are unnecessary too high in 0.8-0.9% range, with cru-wear at 1.2%Si. Except for 10V & 15V extra high C% which would benefit from additional Si%.
Elmax 0.8%Si and M390/20cv 0.7%Si are the other 2 steels, which I mostly will avoid when ht for 64+rc working hardness.
20180330:
After some retrospective looks at sub micron edge holding/retention (fresh sharpen & sealed - hence remove corrosion factor) for various steels. I think, element volume% sum(Cobalt + Silicon) is proportionally tied matrix slip/yield at nano level. Which dictate matrix yield strength at sub micron level - translate to apex width degradation rate.
For 2-3 years now, I couldn't pinpoint why 52100 has better nano edge than W2 (both steels from NewJersey SteelBaron). Respectively, it is 0.07%Si vs 0.21%Si. Blue#2 has 0.16%Si, which seems to has good apex retention width between 0.7-1.0um very well. 52100 sub 0.5um, W2 1.0-2.0um. aebl 2.0-3.0um. niolox 0.5-1.5um. so on... depends on Co+Si element volume%.
Co localize affected matrix is around 45hrc. Si localize induced RA around mart unit & particle matrix is basically at ferrite level - 20 to 26hrc. For high Co% steels, such as maxamet 10%Co + 0.25%Si, sub 2um apex has higher yield strength than with 0.4%Si.
63-64rc overall matrix probably allow 0.2um thinner apex than sub 61rc.
65+rc overall matrix probably allow 0.3um thinner apex than sub 61rc.
^ both can't negate Co+Si affect. So 64-65rc is a good balance point of edge retention (given edge support intended load/usage).
So for good sub-micron edge shaping & holding, I will re-test njsb 52100, cruforgeV, blue#2, niolox. All assuming their CA Specs on Si% is correct. Niolox has good corrosion resistant due to 12.7%Cr however later on I need to further analyze whether Cr acts as a lattice slipper or blocker. At this point, Cr looks like a blocker, since fracture is common failure mode Cr rich matrix.
Other elements on the same periodic table line as Si are most likely be as bad but I ignored them because most steels are relatively clean. Of course, when sum mass% getting past 0.05% - time to pay attention and perhaps avoid such steels.
Last edited:
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... 45% chance of success - yup, quite optimistic!
I will put handles on these V4E blades and stress-tests (maybe destruction) a 0.150" thick one.
