Flow Accelerated Corrosion: Forms, Mechanisms and Case Studies

Flow accelerated corrosion (FAC) is distinct from erosion and is primarily an electrochemical corrosion process aided by chemical dissolution and mass transfer. The forms of erosion including single and dual phase FAC and liquid droplet impingement are discussed and differentiated. The reasons for a maxima being observed in FAC rates at 150-170 °C has been explained as well as high FAC rates owing to an inversion in solubility occurring with pH occurring at temperatures around 300 °C. Experience from examination of FAC affected components establishing signature patterns of single and two phase FAC is presented. FAC control measures are discussed. The data required from laboratory tests is identified and ongoing lab studies to measure solubility of various oxides is presented.