Stainless steel does not rust – under certain circumstances, flash rust can occur on stainless steel. For example, if it wets with very ferrous water, has not been passivated or treated with too harsh cleaners. Flash rust occurs even at elevated humidity.
In contrast to the rust, which penetrates into the metal and destroys it, there is only rust on the surface. In order to remove flash rust on stainless steel, various cleansers are offered on the internet.
Even the most expensive items are not immune to rust. If you rinse them together with items that are not made of stainless steel, the rust that is produced there can be transferred.