Abstract：Flow-accelerated corrosion has plagued the nuclear power industry for years. In the nuclear environment, the protective oxide film of carbon steel or low alloy steel may experience dissolution and destruction under the action of water flow and multi-phase and liquid materials flow, which would lead to a wall thinning process. Flow-accelerated corrosion occurs mainly in the tube-shaped parts, where are strong turbulent flows, under the action of working pressure, sudden shock or impact or the boot loader, damage may be produced in the thinning region, and sudden burst may happen in large devices. The characterization of flow-accelerated corrosion concerns a large area of wall thinning rather than a localized part. In single-phase fluid conditions, when the corrosion rate is high, the corrosion of the metal surface has morphology of U-shaped, scallop-shaped, orange-shaped flaps; while in the two-phase flow conditions, the pipe corrosion has the morphology of the tiger pattern. This paper reviews the flow-accelerated corrosion (FAC), as an important issue related with nuclear safety. The corrosion behavior, mechanism, and key parameters of FAC are outlined. The FAC process in nuclear power plants is characterized. Many influencing factors of FAC processes are analyzed in terms of surface corrosion film, diffusion rate and FAC rate. Although FAC remains a major problem in nuclear power plants, properly designed protection methods, based on the experience and studies of FAC, will improve plant reliability, such as by adjusting water chemical composition to reduce the corrosion rate and by replacing the materials of damaged and sensitive areas.
2010, Vol. 28 
