Accelerated corrosion of 70/30 copper-nickel alloys in sulfide-polluted seawater environment by sulfide

Abstract

The effect of sulfides on the pitting corrosion behavior and film chemistry of 70/30 copper-nickel alloys in aerated seawater was investigated. Sulfides in seawater prevent the formation of protective oxides on the surface of the alloy and alter the morphology and composition of the corrosion products. It results in the corrosion product film consisting of the double layer structure of the loose and porous sulfide-containing outer layer and the dense inner layer. This double-layer structure of the corrosion product film can't alleviate corrosion, but instead accelerates the development of pitting corrosion. The statistical analysis method is used to study the corrosion process of 70/30 copper-nickel alloy in sulfide-containing environment. This work records the trend of pitting corrosion towards the horizontal and longitudinal directions.

Keywords

• Copper-nickel alloy
• Seawater
• Sulfides
• Pitting corrosion
• Corrosion product film