Stress corrosion cracking involves which combination?

Stress corrosion cracking involves which combination?

• A. Wear from friction
• B. Combined action of corrosion and sustained tensile stress
• C. Corrosion with no applied stress
• D. Pitting without stress

Answer: (B)

Stress corrosion cracking happens when a susceptible material is placed in a corrosive environment and subjected to a sustained tensile stress. The environment alone can cause corrosion, and the stress alone can cause deformation, but cracks form and propagate only when both factors act together over time. Crack initiation tends to occur at defects or stress concentrators and then grows, often along paths such as grain boundaries, aided by the chemical attack of the environment. So the critical element is the combination of corrosion and a persistent tensile load; without either the cracking mechanism doesn’t manifest in the same way. Choices involving wear from friction, corrosion with no stress, or pitting without stress don’t produce this crack-growth process.

Stress corrosion cracking happens when a susceptible material is placed in a corrosive environment and subjected to a sustained tensile stress. The environment alone can cause corrosion, and the stress alone can cause deformation, but cracks form and propagate only when both factors act together over time. Crack initiation tends to occur at defects or stress concentrators and then grows, often along paths such as grain boundaries, aided by the chemical attack of the environment. So the critical element is the combination of corrosion and a persistent tensile load; without either the cracking mechanism doesn’t manifest in the same way. Choices involving wear from friction, corrosion with no stress, or pitting without stress don’t produce this crack-growth process.