Filiform Corrosion
Filiform corrosion is a thread-like corrosion phenomenon under paint films that starts at damaged edges or pores and spreads slowly.
Physicochemical Mechanism of Action
Fillet corrosion occurs when a corrosive agent (like water) penetrates a paint layer and starts reacting at damaged spots such as edges or pores. This leads to a slow buildup of corrosion products that spread as filiform structures.
Metallurgical Relevance & Welding Risks
This corrosion can degrade the mechanical properties of the material and lead to cracks or fractures in the workpiece. It can also significantly shorten the service life of components. In the welding shop, it can occur due to incomplete painting or damaged surfaces.
Workshop Practice & Action Guidelines
To prevent fillet corrosion, careful and complete painting is required. The paint layer should be smooth and undamaged. If suspected, remove the paint layers and repaint the material. Regular inspection of surface quality is crucial.