Abstract:The characteristics and concentration depth profile of the corrosion product film of 70Cu-30Ni alloy exposed to seawater in intermittent immersion were investigated. The results showed that the corrosion product film of incompletely recrystallized 70Cu-30Ni alloy is uniform,rich in Ni and Fe and high in seawater species such as O, Ca, Al,etc. This probably is related with the sufficient oxygen provided under such condition.Because of potential difference between deformed and recrystallized grains of incompletely recrystallized Cu Ni alloy, corrosion develops in preference along the grain boundaries of the two kinds of grains and intergranular corrosion occurs.

Key words: Cu Ni alloy seawater corrosion intermittent immersion