2020 Volume 69 Issue 1 Pages 10-16
Corrosion products on the brass surface were characterized by voltammetry with a high alkaline electrolyte solution （6 M KOH＋1 M LiOH）. In addition to copper oxides （Cu2O and CuO）, zinc oxide （ZnO） was also confirmed on corroded brass surfaces. Depending on corrosion conditions, the amounts of the respective oxides formed on brass surfaces were varied. In the corrosion test in which brass is immersed in a NaCl solution （by assuming dezincification corrosion）, Cu2O was selectively formed, and then grew significantly in NaCl solution at the concentration of 0.1％ or less. However, when the concentration exceeded 1％, the formation of ZnO was newly confirmed. It was suggested that the formation and growth behaviors of the oxides on brass should be affected by the diffusion rate of zinc dependent on the concentration of NaCl solution.
