Good test Vermin. Adding other steels into the mixture provides some good data as it introduces potential electrolysis between the dissimilar metals. A very valid concern with these steels. I've been doing this kind of testing for years and can offer a bit of the data I have accumulated.
First of all, H1 seems to be completely impervious to corrosion when exposed by itself to corrosive environments. In other words, place an H1 blank in a salty, corrosive environment and it is my belief based on years of testing that it will never corrode. Now, add in dissimilar metal...let's say a highly stainless hardware (say pins on a fixed blade). Given enough 24/7 exposure (it usually takes a month or two to become visible) the hardware will eventually show some corrosion and that will bleeed onto the H1 and look like surface rust. If you disassemble the knife and clean the rust from the stainless steel off and examine the H1 you will see that the H1 is unaffected, even when examining under magnification.
How does that compare to lc200n? Well, they are very similar actually. If you follow the first part of the experiment, you will find them to be virtually indistinguishable. An lc200n blank can be left in a salty environment almost indefinitely and not succumb to corrosion (at least that is what I've observed after a couple of years). Now, add in the dissimilar metal and you will see a slight difference between H1 and lc200n. The lc200n will show rust residue from the hardware just like the H1 but unlike H1 the lc200n is a little harder to wipe off and if you examine under magnification you will see some slight isolated pitting where the steel reacted to the dissimilar metal.
Anyway, I would say that the above is a clear demonstration that H1 is "more" corrosion resistant than lc200n but this data needs to be considered in context. First it should be noted that NEITHER of the steels shows any edge degradation due too corrosion, even after months and months of exposure. (I would like to hear if there was any change in the edge on that salt op, as that is a very telling piece of data in regards to how the actual steel is reacting). Secondly, it seems that this type of corrosion can be completely controlled by limiting the exposure of the steel to dissimilar metals. In other words, if you had two knives, one in H1 and one in lc200n, and both of them had g10 handles that snapped and glued together without any hardware (like the Waterway) then you would essentially eliminate the corrosion issue altogether. As an example of that, the Waterway in lc200n has had no rust issues compared to my Jumpmaster in H1. That's not about the steels though, its about the exposed hardware (or lack thereof). Last of all, we need to remember that we are talking about reactions to EXTREME environments. I'm sometimes reticent to talk about these differences because they require such a high level of exposure and neglect that they are almost wholly in the world of academic discussions. Both of these steels are light years ahead of ANYTHING else that any company is working with and though H1 might have an tiny edge on lc200n in owning the designation of 100% rust proof, both steels are so far ahead of any other "stainless" steel that they shouldn't even be considered in the same class or context.
I guess the point is that Spyderco is working with two outstanding rust proof steels. One has better edge performance than the other (in plain edge) and one has slightly more corrosion resistance when exposed to dissimilar metals. The corrosion resistance on both is so high that i would never use it as a deciding factor between the two, even in the harsh environments I use them in. The biggest difference between the two steels IMO is pe vs. se performance so I choose accordingly.
