I have used both M-INFI and INFI in wet and dirty conditions, including around and in saltwater. I have also done long soaks (24 hour) on both blades in salt water solutions (1tbsp per cup, or similar, which is really salty). The M-INFI blade was used for over a year without oil of any kind because the person who I lent it to thought it was stainless.
I have noticed that INFI will resist rust stronger than most plain carbon or low alloy steels (L6). For example, a few weeks ago I spent about 6 hours in the rain with a Battle Mistress, PAB from Strider, a Hatchet from Gransfors Bruks and a few saws. What I found was that while in use chopping (alternating every other piece of wood, about 10 minutes in between use per rotation) neither blade rusted. However as soon as I switched to the saws the Gransfors Bruks hatchet rusted readily.
This really isn't a surprise as the hatchet it is most likely a bandsaw steel (L6-like) or something very close to it and they will rust readily if exposed to water. If you really want to see just how easily such steels can rust thenexpose them to fruit juices, the acids will put a patina on them *very* quickly*, just a few minutes. I cut up an apple with one awhile back and before I the tv program I was watching went to commercial all the contact area had turned.
In regards to comparing INFI/M-INFI to stainless steels, most stainless knife alloys would resist the initial formation of rust stronger than INFI/M-INFI. However based on the long soaks I have done, they tend to take much more extensive damage when they do rust. Mainly they suffer extensive pitting which cannot be removed without a surface lapping (or a chemical treatment which will leave pockets in the finish).
For example using identical salt water solutions on VG-10, ATS-34, D2 and INFI. The INFI blade after a mild cleaning (a few passes with a worn scotchbrite pad) was left with a smattering of small black oxide specs (<0.2 mm in diamater). The other blades had sufrace corrosion that was extensive (>cm in size) and deep enough that even a mild sanding did not remove it (the D2 blade was more extensively damaged than the stainless blades). Most of the specs on the INFI blade (Battle Mistress) came off with use. The only ones that remain are not in frequent contact areas.
I should qualify though, that blades will only rust if left *unused* in corrosive enviroments. The hatchet I mentioned in the above for example was cleaned of all the surface rust from abrasion when I switched back to chopping. As well the blade that rusted after cutting the apple was left unused for about 10 minutes after it sectioned the apple.
One other thing, INFI is not as corrosion resistant as the more rust resistant stainless alloys like 440A. I have a 440A fillet blade in a salt water solution now for a week and it shows only a slight surface rusting in a few areas that would wipe off with a cloth. The piece of BG-42 I have in with it is completely covered in deep black and orange oxide. Most high end cutlery stainless blades do not leave a significant amount of free Cr in the steel so their corrosion resistance is low. Doesn't do the steel any good corrosion wise if the Cr isn't free, regardless of the percentage in the mix.
-Cliff
[This message has been edited by Cliff Stamp (edited 05-22-2001).]
