VG 10 Corrosion Resistance

mattz357

mattz357

Joined
Jun 20, 2002
Messages
873
I carried a knife with an S30V blade for a little while, and despite treatments with various lubricants/protectants I still got rust spots on the blade from sweating. Is the corrosion resistance of VG10 any better? Other than the salt series, is anything better?

On an unrelated note, do any other models share the same screw pattern for the clip with the Centofante III? I would like to find a clip that is silver instead of black. Thanks in advance!!!
 
People often strip the paint off the clips. I prefer the more discreet black, but that'd probably look good on the Cento III!
 
what's the finish on the S30V blade you get rust spots on? bead-blasted blades are more prone to rust, then comes the satin finished ones (depending on the grain, the finer, the more rust-resistant), and then mirror finished blades.

about the silver clip, there are threads somewhere about chemically removing the paint off the spyderco's clips, I guess it would be the same for the screws. It looked like very easy D.I.Y. work, I think I'd do it with my Tasman Salt, to get the Ti clip anodized.
 
The corrosionresistance of S30V is gernerally very high. It might develop some surface rust probably because of its surface finish, but it will resist pitting very well. VG-10 should be similar. I doubt that there is a blade steel in the same cathegory that is more corrosionresistant. ZDP and 154CM/ATS34 is less corrosion resistant. Aus6 might have a higher corrosion resistance. H1 is in a league of its own.
 
the S30V blades should be very easy to get the rust spots off of, I cut lemons and raw meat with mine and have never had a problem. VG 10 is about the same. ZDP rusted pretty easily for me. i dont know why. i am not up on steel specs those are just my observations.
 
FWIW, I have had much better luck with VG10. I have had S30V develop light rust spots fairly easily. I think part of the problem is that most S30V blades are not polished to as high a luster as VG10 often is (S30V has a reputation for being difficult to polish).




Frank
 
Not enough experience to tell you about S30V blades, but I've never had any of my VG10 blades rust, despite my use (abuse?). Used my Delica for fishing, hunting, work, etc, and it has not rusted. I do try to keep the blade reasonably clean during use, and clean it thoroughly after getting home, but rarely oil it.
 
The only Spydie I've had develop rust spots was a Moran trailing point with VG-10 blade. It's still one of my favorite knives nevertheless. I never had any problem with S30V or any other Spyderco blade. One of the Spydercoforum members ran a corrosion test on VG-10 and S30V and if I recall correctly the VG-10 developed rust first.
 
Mark J said:
Wondering why it is that ZDP-189 with 20% Chromium is less corrosion resistant than S30V with 14% Chromium?

http://www.agrussell.com/knife_information/steel_guide/index.html

- Mark
Click to expand...

GM is partially right. It is not just the ratio of carbon to chromium, but you need to look at the microstructure and see where the chromium is and what it is doing. Hitachi rates ZDP-189 below ATS-34 in corrosion resistance and that has a pitting potential below S30V so the latter is the most corrosion resistant of the three. Since the microstructure of ZDP is not know you can only make assumptions but it seems reasonable (meaning, there is really no other explaination possible) that more chromium is tied up in carbides, which will not help the corrosion resistance, only free chromium does. In S30V however, there are a few other carbide formers, most notably Va, so it stands to reason that more free chromium is left. So the lesson is really that you can not just simply look at the chromium percentage to determine corrosion resistance.

MacTech did a pretty grueling and interesting corrosion test with saltwater fog and found that S30V might discolor in parts quite quickly, especially where ever there is an easy point of attack, such as close to the etching, but it resists pitting (deep, and growing corrosion) remarkably well. IIRC an S30V Native withstood at least a week in seawater fog.
 
For what it's worth I had a VG-10 Delica hanging in my shower constantly for more than six months to test corrosion resistance and it never even got a single spot on it.
 
440C with a high polish is probably the best stainless for not corroding(except the H series of course). My VG10 Yang kitchen knife got some brown spots that I had to polish out but this was after some really hard kitchen use and it was easily repaired. In many ways the mid grade stainless like 440C ,aus8 and VG10 are better for knives than high end stainless like S30V. They polish up better and are easier to sharpen and get a first rate edge on.
 
HoB said:
GM is partially right. It is not just the ratio of carbon to chromium, but you need to look at the microstructure and see where the chromium is and what it is doing. Hitachi rates ZDP-189 below ATS-34 in corrosion resistance and that has a pitting potential below S30V so the latter is the most corrosion resistant of the three. Since the microstructure of ZDP is not know you can only make assumptions but it seems reasonable (meaning, there is really no other explaination possible) that more chromium is tied up in carbides, which will not help the corrosion resistance, only free chromium does. In S30V however, there are a few other carbide formers, most notably Va, so it stands to reason that more free chromium is left. So the lesson is really that you can not just simply look at the chromium percentage to determine corrosion resistance.

MacTech did a pretty grueling and interesting corrosion test with saltwater fog and found that S30V might discolor in parts quite quickly, especially where ever there is an easy point of attack, such as close to the etching, but it resists pitting (deep, and growing corrosion) remarkably well. IIRC an S30V Native withstood at least a week in seawater fog.
Click to expand...

Thanks for the explanation, HoB. I figured it was more than just the % Chromium, but wasn't quite sure... BTW, are the Hitachi corrosion resistance tables online?

- Mark
 
Another upside to S30V is that it's practically impurity free, and all the addatives (like Va) have an almost perfectly uniform distribution within the microstructure. This also helps alot with rust resistance, not to mention overall toughness.
 
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