Accelerated Corrosion Behavior of B10 Cu-Ni Alloy in Seawater

Abstract

B10 Cu-Ni alloy has good corrosion resistance against seawater. Natural seawater from Xiamen, was used to study the seawater corrosion behaviour of B10 Cu-Ni alloy, H2O2 was added as corrosion accelerator. The whole seawater immersion corrosion simulation experiments were conducted in laboratory. Geometric measurement and electrochemical impedance spectroscopy (EIS) technique were used to obtain the tendency of corrosion rate versus corrosion time. The growth and damage of the oxidation film on the surface of the alloy of 1cm2 working area were characterized by the impedance spectra features with different corrosion time.Scanning electron microscope(SEM),energy spectrum analysis(EDX), X-ray photoelectron spectroscopy(XPS) and raman spectrum were used to analyse the constitution of corrosion product and the corrosion types. The results show that the instantaneous corrosion rate exhibits decreasing first then increasing due to the state of oxidation film. The corrosion products consist of Cu2(OH)3Cl and Cu2O. And the corrosion of B10 Cu-Ni alloy starts with pitting corrosion, then gradually goes through the evolution process of intergranular corrosion to exfoliation.

Keywords

• B10 Cu-Ni alloy
• seawater corrosion
• EIS
• SEM
• corrosion product