Passiválás

Passiválás is a surface treatment process used to enhance the corrosion resistance of metals, particularly stainless steel and aluminum. The process involves creating a protective oxide layer on the metal surface. This layer is typically formed by exposing the metal to a chemical solution, often an acid or a mixture of acids, which reacts with the surface. The resulting oxide film is thin, passive, and adherent to the underlying metal. It acts as a barrier, preventing or significantly slowing down the electrochemical reactions that lead to corrosion.

The effectiveness of passivation depends on several factors, including the type of metal, the passivation solution used, the duration of the treatment, and the temperature. For stainless steel, the passive layer is primarily composed of chromium oxide. This layer is self-healing, meaning that if it is damaged, the chromium in the steel will react with oxygen to reform the protective oxide. For aluminum, the passive layer is typically aluminum oxide. Passivation is a crucial step in many manufacturing processes where metal components are exposed to corrosive environments, ensuring their longevity and functional integrity. It is distinct from plating, as it doesn't add a foreign layer of material but rather modifies the native surface.