Stainless passivation usually identifies the procedure that sorts a defensive oxide film on the metallic surface to make it corrosion-resistant. Stainless steel in a natural way forms an unaggressive film through the connection with atmospheric air.
However, the film made by connection with air (especially in professional areas) will not always offer full cover and there is the opportunity that, if mid-air is polluted by pollutant (flat iron dust particles, chlorides etc.), rather than the unaggressive oxide layer there exists the forming of corrosion or not protecting oxides.
Moreover, regarding pickling by abrasives, stainless cannot be considered passivized since it is not exposed to air for an adequate time after mechanized pickling, and usually professional air is polluted by dust and other steel particles in the suspension system.
Regarding chemical substance pickling, electro-chemical pickling and the process of passivation of stainless steel, the stainless component is totally and uniformly passivized because of the chemical substance providers, as well as the electrolyte + electricity, stimulates the development of the Cr2O3 oxide, which is the adherent and protecting invisible part called “passivation”.
The width of the unaggressive film and therefore the grade of the passivation process relates to the chemical structure of the shower used and is also, therefore, greater regarding chemicals designed to use nitric acid solution ( a strong oxidizer) and hydrofluoric acidity (to eliminate scraps and burns up – toxic).