Yes, I know that tank tracks going through desert sand have their corrosion scratched off. But I am thinking of my Tamiya Pershing and the expensive aftermarket tracks I had to buy for it.

I haven't painted them because the Pershing would be a reconditioned unit sent to Korea during the early summer 1950 part of the war. The metal tracks on construction tractors that I see (the only examples I have to go by) are dirt-clogged but not evidently rusted, and their ground contact parts are relatively shiny. Would tank tracks on newer tanks that have run on hard, dry dirt actually have little or no rust on them?

The moisture in the air would be adequate to induce rust. That time of year in Korea it might still get cool enough to have a bit of dew and it would still be a bit humid but not as bad as it gets during the height of summer and the monsoon season. Metal will rust at the exposure to oxygen, hence oxidation, and moisture can speed up the process. Look at metal objects left in the high and dry deserts. Still rusty. However the movement of the tracks would polish the bare metal pretty quick.

Patrick is correct, although Korea has high humidity year round, except for the extremely cold winter when temps dip well below freezing, and dry air masses out of Mongolia descend on the peninsula (I lived in ROK for three years). However, the rule of thumb to go by is movement— if a tank is moving, it won’t have much rust, unless the tracks are made of low quality steel. Hardened tank track (as on a Pershing) takes a bit of time to rust, not to mention rubberized track blocks don’t show rust. So the rule of thumb is you don’t see much rust on a tank that gets a lot of movement irregardless of the surface it’s travels on. Don’t forget, tanks are inherently “off road” vehicles, and they won’t stay on hard pack roads all the time. In Korea, 1950-53, most roads were still dirt, and where those early Pershing’s were operating, within the Pusan Perimeter, there was a lot of “off road“ travel enough to keep rust at bay.
VR, Russ