S30V 1K SiC and UF abraded surfaces

[jpm2]

Right.


Worth mention again. From my data/observation a carbide decorated on apex, when fracture - the hole/chunk often 1.5 to 5 times of carbide diameter. So for the case above, ram 1+um diamond tip at it, would also dislodge this embedded carbide. Micrographs of EE 10V (plain & etched) - show missing carbide holes, albeit much less than sintered ceramic. Exactly why I recommend 0.25 to 0.1um diamond (est cutting tip be around 1/10 abrasive diameter), which would slowly cut/abrade VC to avoid impact carbide with force can dislodge them.

What causes a hole up to 5 times size of the carbide that occupied it? Is the hole same size as carbide right before it gets tore out, or does hole (socket) gradually enlarge till it can no longer support carbide?

 

[maximus83]

For given SiC & AlO have same binder strength, AlO particle is more durable due to higher fracture strength (lower friability than SiC). Less loose/fractured/broken down AlO grit mean less self-inflicted-binder-plowing, hence surface stay flat longer and duller grit to produce the *bold text* result. Remember I stated in big-font+bold 'Sharp' above, SiC is better. Sure both can glaze but SiC does that less than AlO.

Steel swarf also plays a role in plowing binder away, so increase wear resistant = less wear = less swarf + grit dulled by carbide, lead to more burnishing and if/when inadvertently apexed, then damaged&fractures chunks are much larger than plowing with less burnishing.

Dope AlO surface with loose AlO or SiC grit would help release stone fresh grit. Both can benefit but AlO would benefit from doping more than SiC because of condition above.

I do use AF (fine side of field stone) on steel with less than 5% carbide volume (e.g. 3V, niolox, aebl) - while don't apex or pseudo apex with light pressure to minimize edge crumbling. I've at least 4 cheap coarse grit AlO stones for high pressure plow but recently they are collecting dust. I prefer using slow speed 220 ceramic belt or SiC or sometime 400grit diamond.

OK got it. So: you can use a hard AlOx for coarse work with high carbides, but you think SiC is the most optimal alternative to diamonds for this role.

Side note: You find AF works on steels < 5% carbides, but you don't use it for apexing. If we're talking VANADIUM carbides, that would include my favorites of S30, S35, M390, 20CV, and CTS-XHP. So what are you doing in these cases, just mainly bevel-setting with AF, then do your final apex on higher grit diamonds?

 

[BluntCut MetalWorks]

Carbide nanoscopic surface is rough, lead to much stronger binding than surrounding weak memberance in matrix. When edge is flex upward (mostly lateral force), carbide acts as a torquing lever - taking out chunk taller than footing and often many time wider than carbide diameter. In order to extract carbide from apex with smallest hole (barely larger than carbide diameter) - high energy lateral pinpoint impact(shoot it with 1-2um bullet ) on carbide alone, then fracture will be almost at carbide interface.

What causes a hole up to 5 times size of the carbide that occupied it? Is the hole same size as carbide right before it gets tore out, or does hole (socket) gradually enlarge till it can no longer support carbide?

 

[maximus83]

Sorry, once saw, can't un-see, unless sort of labotomy

For steels with any measurable-usage-affect of VC, I recommend edge trailing on clean 1K SiC stone (SharpPebble) or lightly glazed(some use to simulate 1K) Crystolon F, then refine with the 3K or EE diamond.

Did you buy that $10 3K diamond plate? See & Feel for sure

This worked.

Took the M390 that I had sharpened last night on SP, it was already sharper than a utility edge, but somewhat shy of screaming sharp. Just for fun, took this blade that already had a clean secondary bevel, did light edge-trailing strokes on a clean/damp 1K SP grit. Believe me, I was doing methodical slow strokes at a granny rate of speed, I was terrified of horking my nice bevel. Then 5 ultra light edge-leading strokes per side on DMT EEF, all I have on hand. Then strop. Now we're screaming sharp with a nicely refined edge, judging by my wimpy 30x home magnifying glass , and my lame home sharpness tests. They don't pass the bluntcut school-of-sharpening level of rigor, but good enough for today.

For future reference, I'm trying to figure out what is the least number of steps I can use to get to that level of refined sharpness based on using mostly SiC stones. Say you start with Crystolon coarse, which you need for profile or edge reset. Then you go to fine side, OR to SP 400, don't need both IMO. Now the question: do you need the SP1000, do you need the 3K diamonds, or do you need both to get best results? I can test for both, what's your theory?

 

[BluntCut MetalWorks]

Up to 5% of all but cementite carbide types. Sharp translate to higher PSI = more flat ploughing, minimize rise/taper. 6+% (just a reasonable chosen line) CV shield matrix, thus plow less deep and possibly dull/fracture abrasive tips. Matrix swarf is a nice soft buffer = more cutting length per tip.

For listed steels - SiC then finish on diamond. CTS-XHP can also finish with Alumina or ceramic stone (such as shapton glass/pro). 20cv/m390 has more CrC than VC so bindered-ceramic would work fine - you might not notice most missing VC. Again, talking about submicron edge here.

OK got it. So: you can use a hard AlOx for coarse work with high carbides, but you think SiC is the most optimal alternative to diamonds for this role.

Side note: You find AF works on steels < 5% carbides, but you don't use it for apexing. If we're talking VANADIUM carbides, that would include my favorites of S30, S35, M390, 20CV, and CTS-XHP. So what are you doing in these cases, just mainly bevel-setting with AF, then do your final apex on higher grit diamonds?

 

[BluntCut MetalWorks]

nice. Hahaha edges in my videos aren't that refined nor screaming sharp.

I often like these edges for steels with hard carbide
* Up to 2K whatever EE optional 0.25 diamond trailing swipes (on hard loaded surface)
* Up to 1K whatever then 3K or EE
* 400-600 whatever then EF or 2K or 3K

Too lazy to sculpture an edge to split Feather DE edge

This worked.

Took the M390 that I had sharpened last night on SP, it was already sharper than a utility edge, but somewhat shy of screaming sharp. Just for fun, took this blade that already had a clean secondary bevel, did light edge-trailing strokes on a clean/damp 1K SP grit. Believe me, I was doing methodical slow strokes at a granny rate of speed, I was terrified of horking my nice bevel. Then 5 ultra light edge-leading strokes per side on DMT EEF, all I have on hand. Then strop. Now we're screaming sharp with a nicely refined edge, judging by my wimpy 30x home magnifying glass , and my lame home sharpness tests. They don't pass the bluntcut school-of-sharpening level of rigor, but good enough for today.

For future reference, I'm trying to figure out what is the least number of steps I can use to get to that level of refined sharpness based on using mostly SiC stones. Say you start with Crystolon coarse, which you need for profile or edge reset. Then you go to fine side, OR to SP 400, don't need both IMO. Now the question: do you need the SP1000, do you need the 3K diamonds, or do you need both to get best results? I can test for both, what's your theory?

 

[Chris "Anagarika"]

All good discussion, Q & A

It seems I better stay with VG10 Or ZDP if not have to keep getting fresh diamond tip for the S110V.

@ Luong, what do you mean by flatten apex in earlier instructions? Dull it a la Cliff Stamp?

 

[BluntCut MetalWorks]

Gentle scrape/saw off (stroke along) the apex with EE. Aim for getting a flat square top apex with width less than a micron, then slowly(low impact & burnish) shape to 50-500nm width with 0.25 & 0.1um diamond.

I tried a few times, worked great but my slashing here/there habbit ruined such edge nifty fast.

All good discussion, Q & A

It seems I better stay with VG10 Or ZDP if not have to keep getting fresh diamond tip for the S110V.

@ Luong, what do you mean by flatten apex in earlier instructions?

 

[Chris "Anagarika"]

Gentle scrape/saw off (stroke along) the apex with EE. Aim for getting a flat square top apex with width less than a micron, then slowly(low impact & burnish) shape to 50-500nm width with 0.25 & 0.1um diamond.

Aaargh. Ok thanks ..
Square flat apex it is. When I get doing it, wil post back here.