In localized corrosion, why is it difficult to predict and control?

Localized corrosion is characterized by its tendency to occur in specific areas rather than uniformly across a surface. This highly focused nature makes it particularly challenging to predict and control. Because localized corrosion can manifest in small, often unpredictable spots, it requires targeted monitoring to detect and address the issue before it leads to significant material failure.

Traditional inspection methods may not effectively identify these small, pinpoint areas of corrosion, which are often hidden under deposits or occurring in crevices. Without specific monitoring practices that focus on these vulnerable sites, it's easy to overlook the onset of localized corrosion until it has advanced considerably.

This contrasts with a scenario where corrosion affects the entire surface equally, which would allow for more straightforward interventions. The gradual nature of some corrosion types does not directly correlate with localized corrosion's unpredictable effects. Moreover, localized corrosion can occur in metals of varying strengths, not just those of low strength. Therefore, the distinct and restricted nature of localized corrosion is what makes it particularly insidious and difficult to manage.