The process of treating the surface of stainless steel to clean, polish and to make it less reactive to corrosive elements in the environment. Also know as pickling. Passivation, is a treatment method to protect the metal from corroding through—making the material “passive” to the surrounding environment. Passivation actually and counterintuitively encourages corrosion to occur on the surface, creating a thin layer of a new, non-reactive chemical. This top layer stays tightly bound to the metal