What are typical corrosion indicators in steel members?

• A. Rust staining, flaking paint, surface rust, pitting, and loss of cross-section.
• B. Pitting, loss of cross-section, and cracking.
• C. Rust staining, flaking paint, surface rust.
• D. Delamination.

Answer: (A)

Corrosion indicators in steel members are signs that metal is deteriorating because moisture and contaminants are causing oxidation and coating breakdown. The list—rust staining, flaking paint, surface rust, pitting, and loss of cross-section—covers both surface symptoms and actual material loss.

Rust staining shows iron oxide forming and migrating from the metal into nearby areas, signaling active corrosion beneath or at the surface. Flaking paint indicates the protective coating has failed in spots, letting moisture reach the steel and start or accelerate corrosion under the coating. Surface rust is the initial, uniform layer of oxidation on exposed steel, a clear indicator that corrosion processes are beginning. Pitting represents localized, deep corrosion that can remove metal in small, often hidden spots; these pits can substantially weaken a member even if overall rust coverage seems limited. Loss of cross-section is a direct result of material loss from corrosion and has immediate implications for strength and load-carrying capacity.

Delamination is more associated with layered materials or coatings separating, not a primary sign of steel corrosion itself, and cracking can arise from many causes beyond corrosion alone. The combination of rust staining, flaking paint, surface rust, pitting, and loss of cross-section best represents typical corrosion indicators in steel members.