Passivation creates a chromium rich surface which can form an invisible inert (passive) oxide layer as soon as it is exposed to an oxygen-containing environment (air).
Passivation will not change the appearance of the stainless. If the stainless has been heat treated or welded, the resulting scale or discoloration must be removed by either abrasive methods or by pickling. Passivation will not cause any change to the surface roughness. To verify the effectiveness of the passivation, Allegheny Surface Technology applies saline, copper sulfate, and ferroxyl testing to ensure a successful passivation.