General attack corrosion is best described as which of the following?

• A. A localized pitting process.
• B. A uniform surface loss process without any corrosion products.
• C. A process involving only atmospheric corrosion.
• D. A general, uniform loss across surfaces accompanied by surface roughening and formation of corrosion products.

Answer: (D)

General attack corrosion is a uniform, surface-wide deterioration where the metal is consumed evenly across the exposed area. The metal thins fairly uniformly and the surface becomes rough due to the build-up and sometimes spalling of corrosion products, such as oxides or hydroxides. This is different from localized pits, which are small, deep defects, and it’s not correct to say there are no corrosion products or that it occurs only under atmospheric conditions. The description that best fits is a general, uniform loss across surfaces accompanied by surface roughening and formation of corrosion products.