Ok I'm not the scientist in the family but as I was going to do more work on my Scrappers edge I thought I'd 'torture' him a bit first!

I put my black Scrapper, a nekkid Camillus Kabar type knife (1095 carbon), an Ontario Freedom Fighter Navy knife (440A stainless) and my CRKT Kasper fixed blade (AUS6M stainless) in a mug with about 1.5 to 2" of hot salty water in. There was about a level teaspoon of salt in the water... I got on with chores and left them to marinade for three hours at room temp (22C). On returning I got the knives out of the water, gave them a shake and put them aside for about an hour.

I don't have access to a digital camera so no photos, sorry! I've ranked the knives best to worst for visible effects-

1/Kasper; this was unmarked by its ordeal

2/Scrapper; there were small speckles of surface rust on the bare metal and patches of a black 'bloom' on the edge below the waterline. Above the waterline where vapour had settled were a few tiny rust spots.

3/Ontario Navy; this was similar to the Scrapper but had much more rust spotting below the waterline. It too had black blooms but these were smaller than the Scrappers. Above the waterline vapour had caused a greater area of small rust spots on the blade! Considering this is supposed to be a salty environment blade (440A stainless!!) this level of 'staining' surprised me.

4/Camillus kabar; as mentioned this was a nekkid blade its black phosphur coat having worn away many years ago... it suffered lots of black bloom patches and had LOTS of rust spots above and below the waterline. This poor thing needs a good sandpaper and oil...

This wasn't an exhaustive (or over long) test but I thought it was worth doing.
I was amazed how much better the Scrapper was over the Ontario Navy, I never expected this result. In fairness I could just have a 'poor batch' Ontario Navy and this result is skewed...

I am aware from you guys and the 'yard sight that Scrappers are jackhammer bit tool steel- (and IMHO) they are also corrosion passive! (I'll post later how hard it was to clean up and resharpen my Scrapper and the rest)