What type of corrosion damage projects beyond the surface in such a compact growth it presents a caked appearance, and pits are readily visible to the naked eye?

• A. Major Corrosion
• B. Etching
• C. Caked Rust
• D. Developed Rust

Answer: (C)

Recognize a corrosion form by its appearance: a hard, densely packed crust that actually sticks out from the metal surface. When corrosion products build up into this compact, cake-like layer, it soaks over the surface and creates a noticeable protruding crust. The fact that pits are visible to the naked eye fits this description because the crust can mask underlying metal loss while still showing the pits at its edges or through the crust itself. This combination—a thick, adherent, cake-like growth and visible pits—is characteristic of caked rust. Other terms like etching describe surface dissolution patterns rather than a thick, cake-like crust, and the other options don’t capture that distinctive cake-like, protruding feature.