stresskorrosjonssprekking

Stresskorrosjonssprekking, commonly referred to as SCC, is a phenomenon that affects susceptible materials when they are exposed to a corrosive environment under tensile stress. This combination of factors can lead to the initiation and propagation of cracks, even at stress levels significantly below the material's yield strength. The cracks typically grow slowly, but can eventually lead to catastrophic failure if not detected and addressed.

The susceptibility to SCC is highly dependent on the specific material, the corrosive environment, and the applied stress. For example, certain stainless steels are prone to SCC in chloride-containing environments, while aluminum alloys can be susceptible in chloride or alkaline solutions. The mechanism involves a complex interplay between electrochemical and mechanical processes at the crack tip.

Factors influencing SCC include the magnitude and type of stress (applied or residual), the concentration and type of corrosive species, temperature, and the presence of any surface defects or stress concentrators. Early detection of SCC is crucial for preventing unexpected failures. Inspection techniques such as visual examination, dye penetrant testing, eddy current testing, and ultrasonic testing are commonly employed. Mitigation strategies involve reducing stress levels, changing the corrosive environment, or selecting materials that are more resistant to SCC. Understanding the specific combination of material, environment, and stress is key to preventing and managing this degradation mechanism.