Corrosion behavior of two B10 Cu-Ni alloys in dynamic simulated seawater

The erosion corrosion behavior of two B10 Cu-Ni alloys in a dynamic seawater environment under different flow velocities and erosion time was investigated by using electrochemical techniques and SEM/EDS in a self-made experimental device for erosion corrosion. The results demonstrate that the variation of the corrosion rate of the two alloys with time is similar. The corrosion rate of the two alloys is higher after two hours of immersion and lower after being immersed for eight hours at different velocities. The corrosion resistance of alloy A is generally higher than that of alloy B after being immersed at a flow velocity below 4 m/s for different time. When the flow velocity is higher than 3 m/s and flushing for a long time， the corrosion resistance of alloy B is better. It is related to the grain size and number of twins， as well as the enrichment of Ni and Fe， rather than the chemical states of Ni and Fe. Moreover， Ni and Fe are enriched in the passivation film of the two alloys after long-time immersion at a high flow velocity， which is beneficial for enhancing the corrosion resistance of the passivation film.