Corrosion Resistance Ranking of Stainless Steels

[Chumango]

In order of highest to lowest, as far as I can tell:

S110V
204P/M390/20CV
S90V/20CP
S30V/S35VN

Does your experience agree with this ranking?

Even the "lowest" in this list is good in my experience. I have only seen a *light* spot on S30V despite having it covered with sweat on a hot summer day many times. My son, on the other hand, has pretty corrosive sweat, and he has seen minor rust on S35VN.

[Evil D]

I would probably list VG10 above S30V.

[Surfingringo]

That list looks pretty accurate based on my saltwater testing. I might have ranked s90v slightly above 204p/m390 but those are all pretty close.

[PayneTrain]

My subjective rankings from another post a little while ago:
10: H1, LC200N (based on Surfingringo's report), glass. These things can't rust. Go ahead and try.
9:
8: S110V (really stainless, only managed to get rust spots by leaving joint compound on it to dry, and even then it wiped right off)
7: S90V/CTS-20CP, CTS-XHP, CTS-204P/CPM 20CV/M390
6: VG-10, S30V/S35VN, 440C, Elmax, CTS-B70P, GIN-1, 440A, 12C27, 154CM
5: AUS-8, Cruwear, ZDP-189
4: D2, PSF27, Sleipner
3: M4, 1095, 5160
2: Super Blue (rusts in humid weather if not protected)
1: My car (results possibly skewed by New England's liberal use of super-salts on the roads :rolleyes: )

I may split the 7's and put the M390 variants above the S90V variants based on super scientific sweat testing, but I think it's largely splitting hairs. Other than that, these are still my opinions/absolute truths. :)

[Bodog]

Is someone able to list which steels have the largest amount of free chromium compared to least amount total carbon content? Those ratios would probably be the most accurate.

[Surfingringo]

My subjective rankings from another post a little while ago:
10: H1, LC200N (based on Surfingringo's report), glass. These things can't rust. Go ahead and try.
9:
8: S110V (really stainless, only managed to get rust spots by leaving joint compound on it to dry, and even then it wiped right off)
7: S90V/CTS-20CP, CTS-XHP, CTS-204P/CPM 20CV/M390
6: VG-10, S30V/S35VN, 440C, Elmax, CTS-B70P, GIN-1, 440A, 12C27, 154CM
5: AUS-8, Cruwear
4: D2, PSF27, Sleipner
3: M4, 1095, 5160
2: Super Blue (rusts in humid weather if not protected)
1: My car (results possibly skewed by New England's liberal use of super-salts on the roads :rolleyes: )

I may split the 7's and put the M390 variants above the S90V variants based on super scientific sweat testing, but I think it's largely splitting hairs. Other than that, these are still my opinions/absolute truths. :)

These are fairly accurate groupings IMO. I have a few nitpicks but I think the above makes a for pretty solid reference guide.

[Chumango]

Thanks for your input, guys. I think this is a pretty good general guide, though I am sure things may move around a bit depending on actual use and experience. For example, salt water kayak use is different form my use.

Personally, I would rank M4 above 1095 and 5160, but everyone's experience may be a little different.

[Surfingringo]

Thanks for your input, guys. I think this is a pretty good general guide, though I am sure things may move around a bit depending on actual use and experience. For example, salt water kayak use is different form my use.

Personally, I wold rank M4 above 1095 and 5160, but everyone's experience may be a little different.

And you would be correct. M4 is definitely in a different category. It's a great deal more corrosion resistant than steels like 1095 and 5160. That was my main "nitpick" but it's still a pretty solid list to refer to.

As far as saltwater kayak fishing, thats different than most people's use but it is a good way to check the anti corrosion properties of steel in a short amount of time. I can make any steel rust in a day...except for Lc200n/H1. Your ranking matches up about the same with my experience despite our different usage.

[wrdwrght]

Anyone care to suggest where ZDP-189 fits? I hear tell it's not especially resistant, but I can't get a patina to form naturally on my two Stretches.

[Surfingringo]

Anyone care to suggest where ZDP-189 fits? I hear tell it's not especially resistant, but I can't get a patina to form naturally on my two Stretches.

I have a good bit of experience with cruwear and only a little with zdp 189, but from what I've seen I would put them in a similar category. Neither of them show much patina but both will show rust spots quicker than a typical stainless when left in a corrosive environment. As I said though, my experience with zdp189 is somewhat limited and I only have it in a laminated blade.

[wrdwrght]

Thanks, Lance. My experience with Cru-Wear is similar, so the grouping makes sense to me.

[Northglenn500]

Can I assume 52100 goes with 1095, or is it as rust prone as Super Blue?

[PayneTrain]

See my take on M4 and other non stainless steels I think is the biggest example of other factors coming into play. I'm comparing a Gayle Bradley with the usual satin finish to a 1095 Mora with a near mirror polish. I've freckled my GB with rust a couple times, but my 1095 is still mostly spotless. Not that they've been used in similar ways either. :) So I just throw em all together, except for Super Blue which needs protection more than anything I've owned.

[Bodog]

See my take on M4 and other non stainless steels I think is the biggest example of other factors coming into play. I'm comparing a Gayle Bradley with the usual satin finish to a 1095 Mora with a near mirror polish. I've freckled my GB with rust a couple times, but my 1095 is still mostly spotless. Not that they've been used in similar ways either. :) So I just throw em all together, except for Super Blue which needs protection more than anything I've owned.

Agree. According to specs it should be shirogami, aogami/52100, 1095, then up to M4, etc. In the real world I have a Damascus blade with 1095/15n20 that won't rust unless I absolutely neglect it after it's been damp for awhile, 52100 mirror polished is hard to rust unless I cut some pretty acidic food, 10V I've left covered in blood in a kitchen sink overnight and it didn't rust at all while bead blasted 154cm and S110V got rust spots after sitting in my pocket on a dry day.

Point of the story, bead blasted and/or roughly finished steel changes it all up considerably. So does differing heat treatment steps.

[Liquid Cobra]

I was under the impression that s35vn was more corrosion resistant than s30v.

Am I incorrect?

[Chumango]

I don't think there is much of a difference between S30V and S35VN, at least that I have noticed.

And yes, surface finish plays a very large role in corrosion. Last weekend I went backpacking, and the M4 PM2 I had in my pocket ended up speckled with very small rust spots on the side facing my body (and mostly on the portion of the blade that was not covered by the scale). My brother uses a Gayle Bradley working in his yard and backpacking, and he has rarely if ever had any rust. The GB blade is finished noticeably smoother than the PM2.

[PayneTrain]

Well if so, it's so marginal that you'd be hard pressed to tell a difference. Again, beyond anecdotal, but I've rusted my S35VN but not my S30V, and they have similar finishes. And my B70P spotted in about the same conditions. That's about as precise as my testing will get! But yeah, I think finish and variations in heat treat will ultimately have a larger effect than small differences in chemistry especially when the tolerances in a particular chemistry begin to overlap the tolerances of another similar steel. I think with all the variables involved, most of the steels mentioned can float one or even two rankings on a 10 point scale.

I think what we can all agree on is that nitrogen is witchcraft, S110V really is super, and Super Blue can easily be renamed Super Blue, Black, & Orange. :) Everything else is up for debate.