Satin is the least susceptible, all INFI Busses have the potential to develop some surface rust/oxidation that will leave a stain. On satin blades, sometimes "rust" will develop in the talon holes - a pipe cleaner or whatever else you can think of will knock it right off/out of the talon holes. Big DC and Big SATIN can develop some oxidation just sitting around depending on your climate and how cool you keep your house in said climate. I don't think I have had any satin develop "rust" just sitting around, save one that came with an uneven satin finish that Busse will fix if I send it in.
I lost my NMFBMLE in my yard for a couple days and it endured heavy rain, and sat in standing water. It developed surface oxidation that basically wiped off although did stain, no pitting. It is a user and use cures all.