Effect of in-situ pre-soaking in seawater on the erosion-corrosion properties and micro-mechanism of nickel aluminium bronze alloy.

The effects of pre-soaking in seawater on the corrosion behaviour of the nickel aluminium bronze alloy were examined using electrochemical and erosion-corrosion tests. The surface passive film of the alloy pre-soaked for 30 d consisted of an outer loose CuO film, a middle dense Cu 2 O film, and a denser inner Cu 2 O film contained Al 2 O 3. The corrosion properties of the sample pre-soaked for 30 d were significantly improved, with ∼71% reduction in corrosion rate at 3 m/s compared with the unsoaked sample. Strong bonding between the substrate and passive films formed during pre-soaking effectively inhibited the entry of ions from seawater. • The pre-soaked sample surface corrosion film is divided into three layers. • The middle and inner layers are composed of dense Cu 2 O and thin Al 2 O 3 for protection. • The pre-soaked corrosion film has stronger adhesion to the substrate after erosion. • Significant improvement in erosion-corrosion performance of pre-soaked film sample. [ABSTRACT FROM AUTHOR]