Differences in corrosion resistance between analog steels

[steelcity16]

While most people seems to agree that the performance difference in analog steels (Cruwear/PD-1/Z-Wear or CTS-204P/M390/20CV) are indistinguishable to the end user, I wonder if anyone has done a true hardcore test of corrosion resistance between analog steels?

Sal talking about how he has his MagnaCut blade submerged in salt water and removes, dries, and inspects it 3-4 times a day is the type of test that I would think may end up seeing some differences, especially in the Cruwear/PD-1/Z-Wear family, where they are very stainless by tool steel standards compared to the likes of 4V, M4, Rex45, K390, etc., but there is definitely varying degrees of corrosion/patina if they are neglected. My Cruwear Delica shows a lot of Patina, but no real rust, but my Cruwear Shaman had very tiny rust spots pretty early only but didn't develop patina like the Delica. I am guessing that may be been differences in the way Golden heat treated the Cruwear vs. the way Seki heat treated theirs for the Delica.

I am just curious that if all other aspects of these steels are indistinguishable to 99.9% (if not 100%) of users, maybe there is enough of a difference in corrosion resistance that would make one Cruwear analog win out over the others for future Micarta releases??

[emanuel]

Heat treatment alone on the same steel makes a higher difference in corrosion resistance than any other two different stainless steels with similar makeup. A D2 steel blade that's been heat treated for corrosion resistance to have as much chromium in solution will resist corrosion significantly better than MagnaCut if it was heat treated for wear resistance. I don't see how such a test could be done in a fair way or show subtle difference in similarly corrosion resistance steels; instead imo it will just show off different types of heat treatments.

[cali]

Corrosion resistance also depends on surface finish, which is different in Golden and Seki knives.

A D2 steel blade that's been heat treated for corrosion resistance to have as much chromium in solution will resist corrosion significantly better than MagnaCut if it was heat treated for wear resistance.

In the case of D2 I doubt you can easily dissolve that primary chromium carbides

[JRinFL]

emanuel & cali beat me to it.

[Deadboxhero]

Heat treatment alone on the same steel makes a higher difference in corrosion resistance than any other two different stainless steels with similar makeup. A D2 steel blade that's been heat treated for corrosion resistance to have as much chromium in solution will resist corrosion significantly better than MagnaCut if it was heat treated for wear resistance. I don't see how such a test could be done in a fair way or show subtle difference in similarly corrosion resistance steels; instead imo it will just show off different types of heat treatments.

Nah, going beyond 1900f with D2 is not good, more retained austenite then a -300 Cryo can convert, so essentially, you're stuck with ~6% Cr in solution.

If you run up to 2200°F, you'll get closer to 9%Cr in solution but it won't harden due to being mostly retrained austenite.

Using a high temper with MagnaCut is not going to max out the wear resistance. Overall hardness is more effective which is higher with <900°F tempering.

Moral of the story is most of the features of the steel are locked in place due to the overall chemistry and the balance of carbon and chromium for how stainless a steel can be.

While High temper vs low temper have a big effect we are already assuming the D2 is using a low temper, so it could only be worse with higher temper using up what little free chromium is left for carbides.

[WRB]

My Z-Wear PM Micarta Shaman is very prone to surface rust whereas none of my Cruwear knives have this issue. It was a pretty big letdown because I was ready to give the Z-Carta a ton of pocket time and that got cancelled real quick with summer humidity. My brother in law had the exact same issue with his and brought it up without me saying anything.

Anecdotal, but it's all I have to go by. I don't see myself jumping to buy any Z-Wear again. Cruwear all the way for me.