Corrosion fatigue is a result of which two contributing factors?

Corrosion fatigue is a failure mechanism that occurs when a material is subjected to repetitive or fluctuating stresses in a corrosive environment. The correct answer highlights the two key contributing factors: cyclic stress and corrosion.

Cyclic stress refers to the repeated loading and unloading of a material, which can create small cracks or weaknesses over time. When this cyclic stress is combined with a corrosive environment, such as exposure to moisture, salts, or acidic substances, the material's resistance to fatigue is significantly reduced. The presence of corrosion accelerates the growth of these microscopic cracks, ultimately leading to failure at significantly lower stress levels than would occur in a non-corrosive environment.

In contrast, while static stress, constant tensile stress, humidity, low-frequency vibrations, and exposure to air can contribute to material degradation or affect lifespan, they do not specifically address the combination that leads to corrosion fatigue as clearly as cyclic stress and corrosion do. Thus, the choice that connects these two critical factors accurately represents the mechanism behind corrosion fatigue.