Which term describes dulling of the surface due to uniform attack?

• A. Uniform dulling
• B. Pitting
• C. White powder signs
• D. No signs

Answer: (A)

Uniform dulling happens when the metal is attacked evenly across the entire surface, causing a matte, less-bright appearance as material is dissolved uniformly. This is the classic sign of uniform corrosion.

Pitting is different—it’s localized attack that forms small holes or pits rather than a uniform dulling of the whole surface. White powder signs refer to corrosion products that appear as a powdery coating, not the overall dull finish. No signs would mean there’s no corrosion visible. So the term describing dulling from uniform attack is uniform dulling.