Local element

A localized element in terms of corrosion refers to a specific region on the surface of a metallic workpiece where different electrochemical conditions prevail. These differences may be due to local variability in the composition, structure or surface finish of the metal.

In a local element, galvanic currents occur between different areas of the metal surface, stimulating electrochemical reactions. These currents occur when different parts of the metal are exposed to different electrochemical potentials. The resulting imbalance leads to a type of microscopic corrosion in the area with higher electrochemical potential, while the area with lower potential is protected.

Localized elements are particularly common in heterogeneous materials or alloys, as different metal phases or alloy components may have different electrochemical properties. These differences can be attributed to factors such as grain structures, inhomogeneities or phase differences.

The effects of localized elements can take the form of pitting corrosion, crevice corrosion or other types of localized corrosion phenomena. To minimize such problems, various corrosion protection measures are taken, including the use of corrosion-resistant alloys, surface coatings and specific design and manufacturing techniques.

Knowledge of local elements is important to understand the corrosion resistance of metallic components and to take appropriate measures to prevent or control corrosion. Research and development in this area aims to develop advanced materials and technologies to improve the resistance of metallic structures to corrosion.