Influence of a sol–gel alumina coating on oxidation of X20CrMoV12-1 in air up to 650°C

The Insignificant Improvement of Corrosion and Corrosion Fatigue Behavior in Geothermal Environment Applying Boehmit Coatings on High Alloyed Steels

“…For the preparation of water and ethanol-based sols and coatings, the procedures outlined in [34,35,43,44,[51][52][53], and illustrated in [34] were followed. Initially, an aluminum nitrate (V) solution was heated to 87 • C, and aluminum tri-sec-butylate dissolved in secbutanole was added under vigorous stirring for up to 1 h. After cooling to room temperature, the sol was directly used for the dip-coating process.…”

“…To ensure the required longevity of pipes utilized in Carbon Capture and Storage (CCS) technology, employing protective coatings composed of heat-resistant ceramics is a viable technical solution [34,35]. Alumina coatings emerge as promising choices owing to their high inertness and stability at elevated temperatures [36,37].…”

“…Alumina coatings emerge as promising choices owing to their high inertness and stability at elevated temperatures [36,37]. Various methods, such as plasma spraying, chemical vapor deposition, and ceramic slurry application, are employed to produce thick alumina coatings, while the sol-gel technique allows for the application of thin alumina coatings [34,35,38,39]. Alumina has demonstrated resilience in high-temperature environments and can be effectively applied as a coating through the solgel method [34,36,[40][41][42][43].…”

“…Research by Dressler et al [44] showcased the efficacy of a sol-gel alumina layer, generated via a modified Yoldas sol [41], in providing effective protection for Inconel-718 even after 4000 h of exposure at 800 • C in static laboratory air. Additionally, a 400 nm thick transition alumina layer, applied using the sol-gel method on commercial power plant steel X20, exhibited excellent protection against oxidation in laboratory air up to 650 • C [35]. The infusion of manganese and chromium ions into the alumina layer, leading to the formation of mixed oxides, contributes to the enhanced protective properties of the coating, preventing oxidation.…”

“…The infusion of manganese and chromium ions into the alumina layer, leading to the formation of mixed oxides, contributes to the enhanced protective properties of the coating, preventing oxidation. Furthermore, the avoidance of local defects, attributed to substrate preparation through polishing, is identified as a significant factor in improving the coating process [34,35].…”