||[Jun. 3rd, 2008|11:02 am]
So, if you recall, I bought a bunch of s30v, a high vanadium CPM stainless steel. On Sunday, I broke out a bar, and after looking up the forging information, gave a whack at forging it into a taper for a chef's knife. And another. And a whole lot more.|
This stuff does. not. want. to. move. under. the. hammer. At all. I did five heats, and used the power hammer, and was only able to get about 50% reduction. Trying to forge in bevels was a similar losing situation -- the hammer made an impression, sure, but not much of one. I'm not even going to try to forge the handle to shape, I'll just plasma cut out the shape and grind to match.
S30v should be worth the effort, though. From the spec-sheet:
> CPM S30V is a martensitic stainless steel designed to offer
> the best combination of toughness, wear resistance and
> corrosion resistance. Its chemistry has been specially
> balanced to promote the formation of vanadium carbides
> which are harder and more effective than chromium carbides
> in providing wear resistance. CPM S30V offers substantial
> improvement in toughness over other high hardness
> steels such as 440C and D2, and its corrosion resistance
> is equal to or better than 440C in various environments.
> The CPM process produces very homogeneous, high
> quality steel characterized by superior dimensional stability,
> grindability, and toughness compared to steels produced
> by conventional processes.
(Notice they do not mention forgeability in its benefits list)
I'm really thinking that yeah, I need a forging press. I really want one of the specialty knifemakers forging presses, and don't really want to build my own from scratch. Ron Claiborne makes a good one http://home.comcast.net/~eellis2/EllisCustomKnifeworks/hydraulicpress.html . Wayne Goddard recommended another one, though I haven't gotten a response from the maker about specifications, the Imagination XPress http://www.dfoggknives.com/Xpress.htm
I'm guessing, though, to afford either one, I'm going to have to sell some stuff (Getting married is expensive). The Little Giant, while it's been useful, is really not what I need, so I'm thinking seriously about cleaning it up a bit and putting it up for sale.
While cleaning on Saturday, I found my rayskin, so I can move forward on the tanto project as well.
Just a few more things to go into the dumpster (my back was saying I needed to take yesterday off) then I'll have them come pick it up.
i thought there was a reason they could cast it as a powder, and then grind it? sounds tough!
the working edge on this stuff is very good. i have a small knife with it, and while i don't use it a LOT, hasn't dulled that i can tell, and is still somewhat quite nasty (ask Phil ;>) sharp.
also stupid expensive on "large" knives.
Well, the stuff is "stupid expensive" even as bar stock. I bought an overstock box of 100lbs (though I think there's more than that in there) at about 25% of retail -- cutoffs and random lengths/widths in 1/4" thick. It's pretty neat stuff, though.
2011-04-07 01:06 am (UTC)
may i ask were you got the blankes ? im looking for 1/8 by 6 to 12 inches
Admiral Steel carries it, as does Aldo (njsteelbaron.com).
Also, if I understand how CPM works (and once I have the press I can start making my own alloys, yay!) is you use ferro-alloy powders thoroughly mixed together, which when heated and compressed first fuse together then diffuse the alloying elements across the grain boundaries, resulting in a homogeneous steel. By compressing to full density at welding heat in a controlled atmosphere, you get a bar with no obvious sinter gaps, and the subsequent forging and rolling get you a nice small grain size.