Sorry if this might be in the wrong section, but I wanted someone's opinion on the formation of rust. Do you think that the rate of formation of rust on iron/steel is an exponential growth?... --- Also, some extra. I'm doing an EEI on rusting - basically, I'm trying to find the best methods of protection. In one of my tests, which included a Zinc strip as a sacrificial anode - the iron ended up rusting, even when there was plenty of Zinc remaining. The iron and zinc were touching, so a galvanic cell effect would have been created....I just don't understand why it would have rusted. Also, it was in a sodium chloride solution (Salt Water), so I'm thinking at the moment that the sodium chloride would have had something to do with it.