Carbon steel is the main material for power plants, oil and gas pipelines. Flow accelerated corrosion is the main factor causing pipeline failure in power plants, especially the secondary circuit pipeline system of the pressurized water reactor (PWR) nuclear power plant. In this paper, a home-made flow accelerated corrosion test rig and array electrode technology was used to study the effect of different flow rates on the flow accelerated corrosion rate distribution of 20# carbon steel elbow at 120 °C. The correlation between hydrodynamic parameters and corrosion rate was analyzed based on hydrodynamic simulation. The results show that the maximum corrosion current density is located at the external bending side of the elbow at different flow rates. With the increase of flow velocity, the flow accelerated corrosion rate increased significantly. In addition, the comparison of experimental data and simulation results show that the radial local velocity component can be used as an important parameter to predict the flow accelerated corrosion rate of carbon steel elbow. The empirical formula between the radial local velocity component and the corrosion rate was obtained by fitting based on the least square method. This research can be applied to design optimization, operation monitoring and maintenance strategy formulation of carbon steel elbow transport lines in thermal power, nuclear power and chemical industries.

Keywords： elbow ; flow accelerated corrosion ; electrochemistry ; numerical simulation ; hydrodynamics