Passivation is the process of making a material ‘passive’, usually by the deposition of a layer of oxide that adheres to the metal surface. In air, passivation affects the properties of almost all metals, notable examples being aluminium, zinc, titanium, and silicon (a metalloid). In the context of corrosion, passivation is the spontaneous formation of a hard non-reactive surface film that inhibits further corrosion. This layer is usually an oxide or nitride that is a few nanometres thick.
The stainless-steel passivation process removes all surface impurities and stimulates the development of an oxide film which protects the component from rust and corrosion. In general, all tanks are made up specifically for the job at hand which means you can always be assured of a fresh solution.
Pre-treatment: All components are pre-treated with a degreaser to remove grease, oils, coolants, machining chips and other microscopic contaminants.
Nitric Acid Passivation: Suited to Chromium-Nickel Grades (300 Series) and Grades with 17% Chromium or more (except 440 Series).
Nitric Acid with Sodium Dichromate Passivation: Suited to straight Chromium Grades (12-14% Chromium), High Carbon-High Chromium Grades (440 Series) and Precipitation Hardening Stainless.