Menipo wrote: ↑Thu Oct 08, 2020 12:07 pm
Cycletroll wrote: ↑Thu Oct 08, 2020 11:45 am
Larrin addresses the carbide type in 204p class steels and why they are easier to sharpen:
"Microstructure
The high chromium content in M390 means that less of the high hardness vanadium carbide is present in the steel, and the majority of carbide is the lower hardness chromium carbide. The vanadium does increase the hardness of the chromium carbides, however. You can read more about the interaction between different elements for carbide formation in this article on carbides. Chromium carbides tend to be larger than vanadium carbides in power metallurgy steels which limits toughness, but they are easier to sharpen because they are softer than common sharpening abrasives like aluminum oxide. Bohler reports that M390 has about 18% chromium carbide and 2.5% vanadium carbide [20], and in my metallography I found about 22% carbide. This high carbide volume results from the high carbon and chromium in the steel, which puts its carbide content similar to steels like Maxamet, S90V, and 15V. The high volume of chromium carbide means that M390 has a larger carbide structure than those steels, however. Stainless steels with a lower carbide content like S35VN, S45VN, or Vanax also have a finer microstructure. You can compare with many other steels in this article which contains all of my micrographs."
Citation from:
https://knifesteelnerds.com/2020/06/01/ ... -and-204p/
For what it's worth I too find it much easier to sharpen than the steels with more vanadium and tungsten carbides. That being said, proper stones and technique make any steel "easy to sharpen", some just take a little more time
Thanks! It makes sense. Some videos that I saw (like the one that I link below) show that sharpening S110V is not so difficult but on the other side I have read a lot of opinions stating the contrary. So I got confused with the point of reference (S110V) to compare 204p (in terms of ease of sharpening).
https://www.youtube.com/watch?v=XOHusrAPOEw
From what you and Vivi said, it is clear that 204p is easier to sharpen than S110V. So if S110V is a sharpening nightmare (as many say), 204p is a "nightmare minus"

. And if S110V is not so complicate (as the guy in the video says) 204p will be even easier to work with. The conclusion is clear: I will seriously consider to add a 204p blade to my collection
S110V is difficult to put a fine/polished edge on, or at least a polished edge that's actually sharp... However low grit working edges are actually very easy to achieve, so long as you have diamond, CBN or ceramic stones. The best thing about that "quirk" is that S110V is most useful with exactly that sort of edge!
As far as "super steels" that take a good and lasting fine edge, the M390 family is probably the easiest to sharpen and one of the best stainless alloys for that purpose IMO.
Don't be afraid of high carbide stainless, just don't treat it like carbon steel or older stainless alloys and you'll have great results!