How Does Stainless Steel Passivation Process Work? What is the meaning of passivation and how does it work? How to passivate the parts of the stainless steel after machining operations? These are a few questions asked by the companies or manufacturers regarding the Stainless Steel Passivation Process. What is the passivation of stainless steel? Passivation is a commonly used process for mental finishing to prevent corrosion. In stainless steel, either nitric acid or citric acid is used for the passivation process in order to Remove Rust from Stainless Steel. The chemical treatment results in the formation of a protective oxide layer with less possibility to chemically react with air and lead to corrosion. Passivated stainless steel prevents rust.