What type of corrosion damage involves advanced stages of etching, pitting, developed or caked rust which affect the form, fit or function of an item. It is not readily removable and projects beyond the surface?

• A. Major Corrosion
• B. Minor Corrosion
• C. Etching
• D. Pitting

Answer: (A)

When corrosion has progressed to the point where etching, developed or caked rust, and pitting have altered the item’s form and function and cannot be easily removed, with corrosion products projecting beyond the original surface, you’re looking at major corrosion. This level indicates significant material loss and deformation that affects fit or operation, not just surface discoloration. Etching describes chemical roughening of the surface, which can occur without changing overall dimensions; pitting are localized holes that can be deep but may be confined to small areas. Minor corrosion remains superficial and removable, without affecting the item’s geometry or performance.