Stainless Steel Passivation Bath
A stainless steel passivation bath is an aqueous solution of citric acid or nitric acid in which cleaned stainless steel components are immersed. The goal is to form a dense, closed protective layer.
Physical-Chemical Mechanism of Action
Citric acid or nitric acid reacts with the stainless steel to form a dense chromate layer on the surface. This process prevents the metal from corroding in later environments.
Metallurgical Relevance & Risks in Welding
The passivating layer protects the surface from corrosion and increases the service life of the components. Missing or incomplete passivation can lead to corrosion susceptibility, which is particularly dangerous in chemically demanding environments.
Workshop Practice & Instructions
Use a concentrated solution of citric acid or nitric acid. The concentration should be between 5% and 10%. The components should remain in the passivation bath for at least 24 hours to form a dense layer. After passivation, the metal must be thoroughly dried before further processing.