Scrub the stainless steel pan. What color is the black color on the towel?
The name of stainless steel is because it won't be oxidized by oxygen in air,
Rust is the oxidation of metal surface and the formation of oxide layer, so the stainless steel pan surface of the black color is not rust, it should be fired when the ash generated by heating, can be washed with steel wire ball dipped in detergent cleaning.
