I suppose that might be true, but have you actually done the math here?
If it dries say 50 times faster, does iron rust more than 50 times faster at 400F than at 70?
I have no way of knowing either way, but I've got a cast iron pan that belonged to my great grandmother and I remember my grandmother heating it to dry it off. My mom did the same with it, and now I've done the same--no rust.
I don't doubt that warm metal rusts faster, just how much faster.
There's a pretty big difference between drying something in a warm stove vs applying a direct flame to it on the stove top.
It takes just a few minutes to get the skillet hot enough where the water pretty much instantly evaporates. I'd imagine putting it in a warm stove took much longer to completely dry it.
What I said was that if you are heating the iron in order to speed up evaporation to avoid rust, you are being counter productive. You will avoid more rust (if any would be formed in the fist place), by just letting it air dry.
I don't know what you said, then. People are saying we put our cast iron on the burner for a couple minutes to dry it off and you're saying the direct flame will cause it to rust.
In my house, we stove-dry pans constantly, precisely to prevent rust, and we never get any. It's not intentionally an "experiment", but it's enough to make me think there's an issue with your methodology.
You probably would not get rust anyway, so stove drying isn't hurting anything much.
But it's certainly not helping.
The methodology was not complicated: I washed some porous/rough metal under the faucet, dried it with a paper towel, then put one piece in the oven at 170F, one on the table.
If it dries say 50 times faster, does iron rust more than 50 times faster at 400F than at 70?
I have no way of knowing either way, but I've got a cast iron pan that belonged to my great grandmother and I remember my grandmother heating it to dry it off. My mom did the same with it, and now I've done the same--no rust.