Pickling passivation

Although stainless steel is a kind of steel which is difficult to rust, it is not because of its corrosion resistance, but because of the acid film formed on its surface called passivation film

Pickling is carried out before the passivation process to remove dirt and clean parts.

Passivation is a post-processing process. The ultimate purpose of passivation is to restore the original properties of the surface by protecting the oxide film, thus making the surface more passive and corrosion resistant.