Stress corrosion cracking is an anodic process, and what protective measure is effective remedial action?

• A. Passivation treatment
• B. Cathodic coating
• C. Electroplating
• D. Cathodic protection

Answer: (D)

Stress corrosion cracking is driven by anodic dissolution at the crack tip under tensile stress in a corrosive environment. The most effective remedial action is to push the metal potential to a more negative (cathodic) value, which suppresses the anodic reactions that fuel crack propagation. Cathodic protection achieves this by making the structure the cathode—either with sacrificial anodes or an impressed-current system—so the crack-tip region experiences reduced anodic dissolution and growth slows or stops. Other approaches like passivation or coatings may help general corrosion resistance, but they don’t reliably prevent SCC under active stress and aggressive environments, especially at evolving crack surfaces.