Passivation Film Integrity
Passivation film integrity describes the quality state of the protective oxide layer on corrosion-resistant metals. High integrity prevents pitting corrosion and increases service life.
Physical-Chemical Mechanism of Action
Passive film integrity refers to the stability of the protective oxide layer that forms on the metal surface. This layer prevents corrosive substances such as oxygen and water from reaching the metal directly.
Metallurgical Relevance & Welding Risks
Inadequate passive film integrity can lead to pitting corrosion, significantly shortening the material's service life. This occurs when the oxide layer is interrupted or damaged, e.g., by chemical attack or mechanical stress.
Shop Practice & Action Guidelines
To ensure high passive film integrity, the following measures should be taken:
• Use corrosion-resistant materials with stable oxide layers.
• Keep the material surface clean and free from dirt and corrosive substances before welding.
• Choose suitable welding processes that do not damage the oxide layer (e.g., TIG welding).
• Apply a corrosion-inhibiting surface treatment after welding.