Cracking under the combined action of corrosion and tensile stress is referred to as:

• A. Fatigue cracking
• B. Creep cracking
• C. Stress corrosion cracking
• D. Tensile stress cracking

Answer: (C)

Stress corrosion cracking is cracking that occurs when a material is exposed to a corrosive environment while under tensile stress, allowing cracks to initiate and grow even at stresses below the yield strength. The environment chemically interacts with the stressed metal to promote embrittlement and crack propagation, often along grain boundaries, producing cracks that can advance slowly over time. This is distinct from fatigue cracking, which is driven by cyclic loading, and from creep cracking, which requires high temperature and time-dependent deformation. The combination of a corrosive environment with tensile load specifically describes stress corrosion cracking.