CORROSION UNDER INSULATION OF CARBON STEEL AND THERMALLY SPRAYED ALUMINUM (TSA) COATING

Abstract

Corrosion Under Insulation (CUI) is a critical challenge in industrial applications due to its hidden and potentially severe damage. This research investigates CUI mechanisms through forensic analysis of rust scale samples from diverse industrial settings, emphasizing environmental and operational impacts. Comparative studies of laboratory and field samples highlight insulation aging's role in CUI, stressing the need for realistic simulations. A case study on premature boiler tube coating failure underscores the importance of material selection and maintenance in CUI prevention. Additionally, the performance of Thermally Sprayed Aluminum (TSA) coatings is examined under CUI and immersion conditions. Microstructural analyses reveal significant degradation challenges, particularly under moisture-saturated thermal insulations, due to factors like flashing moisture and iron dissolution. These findings provide critical insights into improving TSA coatings and advancing corrosion resistance strategies in industrial settings.