Example of the many complex stages of corrosion, demonstrated in the case of localized corrosion of a corrosion resistant alloy (CRA), where a passive film protects the alloy and local breakdown and localized corrosion occurs. The metallurgy and thermodynamics establish the possible identity of the passive film and the thermodynamic driving force for its formation. The (blue) stages in the top row involve passive film growth and interaction with the environment starting with Cl⁻ adsorption, and leading to a variety of phenomena such as Cl⁻-induced changes in surface energy, defect creation, and coalescence, which eventually enable breakdown events. Breakdown and metastable pitting occur in certain environments, while certain high-rate corrosion processes occur, that either transition to stable pit growth or become limited by metastable pitting and subsequently repassivation. At this point, the process starts over again with oxide film growth and possible breakdown. However, if propagation continues and mature pits grow, then even more advanced modes of corrosion are possibly triggered that can lead to other kinds of damage accumulation.