Corrosion Behavior for Thermal Insulations at Ambient Temperatures

Abstract Thermally insulated systems are often subjected to temperature swing or are decommissioned for various operational, maintenance and economic reasons. This study is a follow up research work to previously published research work by the authors that investigates the CUI of carbon steel coupons applied with fibrous stone wool insulation under ageing condition. This work is aimed at checking the consistency/inconsistency of corrosion behavior of stone wool insulation and hydrophobic blanket under ambient temperature conditions. Thermally insulated assemblies were submerged in freshwater for a week followed by outdoor exposure for 1 year. The volume loss from the coupons was characterized via 3D laser scanning followed by conversion to weight loss and corrosion rates. Pit depths were characterized using confocal laser scanning. In addition, the scale was characterized using X-ray diffraction (XRD). The possible reasoning in corrosion rate(s) deviations from previous study are also discussed.