What type of corrosion is characterized by localized attack on the surface of a material?

Pitting corrosion is characterized by localized attack on the surface of a material. This form of corrosion leads to the development of small, deep pits or cavities, which can be quite detrimental, particularly in materials that are otherwise resistant to uniform corrosion. The localized nature of pitting can make it difficult to detect and predict, as it may not show any signs of corrosion over larger surface areas, thus remaining concealed until significant damage has occurred.

Pitting typically occurs in environments where the protective oxide layer on a metal surface is disrupted, allowing ions to concentrate in a small area and create a more aggressive localized environment. Factors that influence pitting include the presence of chlorides, stagnant solutions, and varying temperatures or oxygen levels. Understanding pitting corrosion is crucial for materials selection and the design of components in various industries, particularly in environments where localized damage can lead to catastrophic failures.