What term describes the brittle failure of an otherwise ductile material resulting from corrosion and tensile stress?

• A. Environmental Cracking
• B. Stress Corrosion Cracking
• C. Pitting
• D. Uniform Corrosion

Answer: (A)

Stress corrosion cracking is the process where a ductile metal fails brittly due to the combined effects of a corrosive environment and tensile stress. The environment facilitates crack initiation and makes crack propagation easier, so cracks grow with little or no plastic deformation and the component can fracture suddenly under load. This is different from pitting, which is localized corrosion forming pits but not necessarily a rapid crack under stress, and from uniform corrosion, which involves even material loss without crack formation. Environmental cracking is a broader term for cracks caused by environmental factors, but the specific mechanism described here—brittle fracture from corrosion under tension—is best described as stress corrosion cracking.