I guess it could eventually get buried, but I'd expect that to also be a slow process on most parts of the planet, for similar reasons. The only forces seriously driving weathering on the planet are radiation and wind—the radiation's pretty bad but not a problem for metal + some rocks that were already on the surface, at least over a span of a couple decades, and the wind just can't deliver much force because the atmosphere's so very thin (that's also why it's fairly difficult to fly on Mars).