Which statement about fretting corrosion is true?

• A. It occurs where there is slight relative movement between parts and corrosion residues are not readily removed.
• B. It only occurs in high-temperature environments.
• C. It requires complete absence of moisture.
• D. It forms only on non-metallic materials.

Answer: (A)

Fretting corrosion happens at the tiny sliding interface between two parts. When there is slight relative movement, the protective oxide film or lubricants get worn away and the debris and moisture that remain in the contact area are hard to remove. That combination—mechanical wear plus chemical attack in the confined gap—accelerates corrosion right at the surface where the parts touch. It doesn’t require high temperatures, and moisture or contaminants often play a role in speeding it up. It also isn’t limited to non-metallic materials; metals in contact can frett and corrode under these conditions. So the statement that best describes fretting corrosion is that it occurs where there is slight relative movement between parts and corrosion residues are not readily removed.