Marine Corrosion Performance of Copper Alloy UNS C69100

摘要

Tungum alloy (UNS C69100) is an aluminum-nickel-silicon brass and is reported to have a good corrosion performance in marine environments (fully wetted, splash zone and atmospheric conditions). In order to gain an in-depth understanding of the marine corrosion performance of this alloy, electrochemical test methods including open-circuit potential, electrochemical impedance spectroscopy, potentiodynamic polarization, and zero-resistance ammetry were used for corrosion investigation of UNS C69100 in a 3.5 wt.% sodium chloride aqueous testing solution, in combination with optical microscopy and scanning electron microscopy. The corrosion properties of UNS C69100 obtained by electrochemical methods were also compared with six alternative alloys: UNS S31603, UNS S31254, UNS S32750, UNS N04400, UNS N08904 and UNS C36000. Galvanic coupling behavior of wrought UNS C69100 bar and seamless tubing against these six alloys in a 3.5% NaCI solution for 30 days immersion are also reported in this paper.