Which of the following is NOT one of the nine forms of corrosion?

• A. General
• B. Localized
• C. Galvanic
• D. Oxidative wear

Answer: (D)

This item tests your ability to distinguish true forms of corrosion from a wear-based process. Corrosion forms describe how metal deteriorates due to electrochemical or environmental attack, not how it wears away under mechanical action. General (uniform) corrosion, localized corrosion (such as pitting or crevice corrosion), and galvanic corrosion are all classic corrosion forms because they describe distinct electrochemical attack modes that cause material loss.

Oxidative wear, on the other hand, is a wear mechanism where oxidation occurs at the surface as the metal is worn by friction or contact. It combines oxidation with mechanical wear, but it’s categorized under wear/tribology rather than as a corrosion form. So oxidative wear is not one of the nine corrosion forms.