Passivation Immersion System
A passivation dip tank is a device that immerses metal parts in an oxidizing solution to form a chromium oxide layer and increase their corrosion resistance.
Physico-Chemical Mechanism of Action
Metal parts are immersed in a specific solution (often a sulfate or chloride bath). The metal's surface reacts with ions in the solution, forming a closed chromium oxide layer that prevents corrosion damage.
Metallurgical Relevance & Welding Risks
Passivation increases the service life of metals in corrosive environments. However, incorrect solution concentrations or excessive immersion times can cause over-passivation, impairing mechanical strength and contaminating the material.
Workshop Practice & Instructions
Use a solution with a pH between 2 and 4. Immersion time varies by metal type and application, typically 5-10 minutes. Ensure the parts are clean before immersion to achieve uniform passivation.