How does stress cell corrosion occur?

Stress cell corrosion occurs when variations in stress create differences in electrochemical potential within a material, leading to localized corrosion. In regions of high stress, the metal can become anodic, meaning that it tends to lose electrons and corrode more rapidly. Conversely, areas under lower stress conditions can become cathodic, where they gain electrons and are less prone to corrosion. This differential activity creates an electrochemical cell and accelerates the corrosion process in the high-stress areas.

Understanding this mechanism is crucial for engineers, as it helps in predicting and mitigating failures in structural components subjected to dynamic loads or other stress-inducing conditions. For example, in metals that experience bending or tension, stress cells can form, which significantly impacts the material’s integrity over time.

In contrast, mechanical fatigue, while related to the overall degradation of materials under stress, does not uniquely explain the electrochemical aspect of stress cell corrosion. The impact on plastics typically arises from different mechanisms, such as environmental stress cracking, rather than the process described. Furthermore, while humidity can influence corrosion processes, stress cell corrosion can occur in a variety of environmental conditions, not solely under high humidity. Thus, the statement regarding anodic and cathodic potentials in conjunction with stress levels concis