What does cathodic disbondment refer to?

Cathodic disbondment refers to the separation of a protective coating from the substrate surface, often caused by the electrochemical reactions occurring during cathodic protection processes. This phenomenon can occur when coatings are subjected to conditions such as prolonged exposure to moisture or electrolyte solutions, leading to a loss of adhesion between the coating and the underlying material. The separation is typically exacerbated by the generation of hydrogen gas at the cathode, which can create stress at the interface and contribute to the coating's delamination.

Understanding this concept is crucial for coating inspectors, as cathodic disbondment can significantly impact the effectiveness of protective coatings, allowing for corrosion to reinitiate on the substrate. This makes it essential to evaluate the integrity of coatings in environments where cathodic protection systems are in place.