Which corrosion form involves peeling or flaking along grain boundaries, often seen in certain alloys?

Which corrosion form involves peeling or flaking along grain boundaries, often seen in certain alloys?

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

Answer: (C)

Exfoliation corrosion describes a severe intergranular form where the metal corrodes along grain boundaries and the corrosion products build up between grains, forcing layers to separate and peel away from the surface in thin sheets. That peeling or flaking is the hallmark, and it often occurs in certain aluminum alloys under the right combination of corrosive environment and stress. Other forms don’t exhibit that distinct delamination: uniform surface corrosion is a smooth, even attack across the surface; pitting forms small, localized holes; intergranular corrosion is attack along grain boundaries but without the characteristic layered flaking.

Exfoliation corrosion describes a severe intergranular form where the metal corrodes along grain boundaries and the corrosion products build up between grains, forcing layers to separate and peel away from the surface in thin sheets. That peeling or flaking is the hallmark, and it often occurs in certain aluminum alloys under the right combination of corrosive environment and stress. Other forms don’t exhibit that distinct delamination: uniform surface corrosion is a smooth, even attack across the surface; pitting forms small, localized holes; intergranular corrosion is attack along grain boundaries but without the characteristic layered flaking.