Environmental assisted cracking (EAC) occurs due to a combination of three primary factors; the type of material, the applied mechanical stress, and the corrosive environment. EAC encompasses various mechanisms, including stress corrosion cracking (SCC), hydrogen embrittlement (HE), and corrosion fatigue (CF), among others.
Corrosion damages that occur above 200-260°C (392-500°F) are commonly classified as high-temperature corrosion mechanisms. High-temperature corrosion reactions typically involve direct interaction with oxygen (oxidation), molecular hydrogen (HT Hydrogen Attack), or species such as sulfur (sulfidation, high-temperature H2-H2S corrosion).
These types of failures originate from the mechanical properties of metallic materials, which are linked to their specific crystal structure, grain sizes, and types of dedicated phases formed, among other factors. Parameters such as hardness, yield strength, and ductility tend to change based on process variables like elevated temperature, duration of exposure, and the presence of a corrosive environment. Consequently, the mechanical properties of metals gradually deteriorate over time, leading to failures. Predicting or quantitatively measuring these types of failures is challenging due to the multidimensional correlations between various parameters and the specific structure of metallic crystals.