Intergranular erosion corrosion of pure copper tube in flowing NaCl solution

We investigated the erosion corrosion behavior of a commercial copper tube in 1 wt% NaCl solution using a self-built loop apparatus, and revealed effects of flow velocity on corrosion layer evolution that explains the flow velocity dependent corrosion rate of copper tubes in application. Furthermore, the intergranular erosion corrosion forms the detached and partially oxidized copper grains with nut structure. From core to shell, the compositions are supposed to be copper, copper-based oxygen solid solution, Cu2O with oxygen vacancies, Cu2O, and Cu2O with copper vacancies. These findings provide deepened understanding of erosion corrosion behavior of copper and copper alloys.