Who said that cast iron pots will rust?

I will. Metallic iron is exposed to air and easily oxidized (rusted) when exposed to oxygen. Because iron is an active metal, its activity is second only to aluminum and zinc. In order to delay rust, the factory "passivates" or coats the surface of iron cookware, so that it is not easy to rust. For low-grade cookware, we can "oil" ourselves after buying it: heat the iron pan to extremely hot, rub the surface of the iron pan repeatedly with cooking oil, and wash it once or twice. After cooking, dry and grease. Cooked for a long time, the surface of the pot will naturally "passivate".