Intergranular corrosion may not be detectable even by careful visual inspection.

Intergranular corrosion may not be detectable even by careful visual inspection.

• A. True
• B. False
• C. Sometimes
• D. Not applicable

Answer: (A)

Intergranular corrosion is attack that travels along the grain boundaries of a metal, often promoted by sensitization in stainless steels where chromium is depleted at the boundaries. Because the corrosion progresses along these microscopic boundaries, the surface can look relatively normal even as the boundaries are being undermined internally. In other words, you can have significant degradation along grain boundaries without obvious surface pits or discoloration, so careful visual inspection may miss it. Detecting this type of corrosion often requires metallographic inspection or specific corrosion tests, not just a visual check. That’s why the statement is true.

Intergranular corrosion is attack that travels along the grain boundaries of a metal, often promoted by sensitization in stainless steels where chromium is depleted at the boundaries. Because the corrosion progresses along these microscopic boundaries, the surface can look relatively normal even as the boundaries are being undermined internally. In other words, you can have significant degradation along grain boundaries without obvious surface pits or discoloration, so careful visual inspection may miss it. Detecting this type of corrosion often requires metallographic inspection or specific corrosion tests, not just a visual check. That’s why the statement is true.