What situation can accelerate the rate of corrosion?

What situation can accelerate the rate of corrosion?

• A. The stresses encountered during operation
• B. Absence of moisture
• C. Low temperature
• D. Clean metal surfaces

Answer: (C)

Stresses encountered during operation can accelerate corrosion because mechanical tension or compression promotes crack formation and disrupts protective films on the metal surface. When a metal is under stress, tiny flaws and crack tips become anodic sites where metal tends to dissolve faster in the surrounding electrolyte. This is the essence of stress-corrosion processes: the combination of a corrosive environment and applied or residual stress speeds up material loss beyond what a static, unstressed surface would experience. In contrast, absence of moisture removes the conductive medium needed for electrochemical reactions, so corrosion slows or stops. Low temperature generally slows the rate of electrochemical reactions, reducing corrosion speed. Clean metal surfaces reduce initiation sites and contaminants that can drive localized attack, also slowing corrosion. So the factor that truly accelerates corrosion among these choices is the stresses encountered during operation.

Stresses encountered during operation can accelerate corrosion because mechanical tension or compression promotes crack formation and disrupts protective films on the metal surface. When a metal is under stress, tiny flaws and crack tips become anodic sites where metal tends to dissolve faster in the surrounding electrolyte. This is the essence of stress-corrosion processes: the combination of a corrosive environment and applied or residual stress speeds up material loss beyond what a static, unstressed surface would experience.

In contrast, absence of moisture removes the conductive medium needed for electrochemical reactions, so corrosion slows or stops. Low temperature generally slows the rate of electrochemical reactions, reducing corrosion speed. Clean metal surfaces reduce initiation sites and contaminants that can drive localized attack, also slowing corrosion. So the factor that truly accelerates corrosion among these choices is the stresses encountered during operation.