API 571 Certification (Corrosion & Materials) Practice Test

The term "corrosion fatigue" specifically refers to a failure mechanism that arises from the combined effects of cyclic loading and a corrosive environment. This phenomenon occurs when materials are subjected to repeated stress, which can lead to the development of micro-cracks. In a corrosive environment, these micro-cracks are exacerbated by the presence of corrosive agents, accelerating the degradation process.

As the material experiences continued cyclic loading, the cracks can grow and propagate, ultimately leading to sudden failure. This distinguishes corrosion fatigue from other types of corrosion, as it highlights the interaction between mechanical fatigue and corrosion processes. Understanding this concept is crucial for assessing material integrity in applications where both factors are present, such as structural components in chemical plants or offshore structures where both stress and corrosive conditions exist.