Titanium is a reactive metal, meaning it spontaneously forms as natural oxide film (mainly TiO2) in the presence of any oxygen. Whenever there is any amount of air or water in a process stream or environment, the oxide film forms and protects the metal from corrosive attack. If the film is scratched or damaged, it repairs itself instantly. The highly-adherent film is exceptionally resistant to a broad range of acids and alkalis.
This is the main reason why titanium is widely used for the realization of a wide range of galvanic/anodising equipments such as Anode baskets, racks, jigs, serpentine coils.