Lesson-specific original diagram for Corrosion as an electrochemical process. Model: coupled anodic/cathodic sites corrosion current. It supports this lesson focus: Corrosion is a distributed electrochemical process influenced by water, ions, oxygen, dissimilar metals, coatings, and local chemistry. Text-only equivalent: use the model statement, identify variables/species, then connect the representation to the lesson calculation and evidence check.