Which corrosion is commonly associated with excessive grain boundary attack and exfoliation?

Which corrosion is commonly associated with excessive grain boundary attack and exfoliation?

• A. Uniform Surface Corrosion
• B. Pitting
• C. Intergranular Corrosion
• D. Exfoliation Corrosion

Answer: (D)

Exfoliation corrosion is a form of intergranular attack where corrosion occurs along the grain boundaries and the products between grains push the layers apart, causing the surface to peel or flake off in sheets. The key here is the combination of aggressive attack along grain boundaries and the resulting separation of surface layers, which gives a peeling appearance. Uniform surface corrosion is even thinning across the surface, not tied to grain boundaries. Pitting is localized pits, not layer peeling. Intergranular corrosion happens along grain boundaries, but without the characteristic peeling of layers seen in exfoliation.

Exfoliation corrosion is a form of intergranular attack where corrosion occurs along the grain boundaries and the products between grains push the layers apart, causing the surface to peel or flake off in sheets. The key here is the combination of aggressive attack along grain boundaries and the resulting separation of surface layers, which gives a peeling appearance.

Uniform surface corrosion is even thinning across the surface, not tied to grain boundaries. Pitting is localized pits, not layer peeling. Intergranular corrosion happens along grain boundaries, but without the characteristic peeling of layers seen in exfoliation.