Stress corrosion cracking of aluminium brass induced by marine organism fouling

Abstract

Copper and its alloys are widely used in marine applications due to their good corrosion resistance and excellent antifouling ability in marine environments. When resistance to seawater is essential, aluminum brass is used. This chapter examines the corrosion resistance of tubes and plates made of aluminum brass, and exposed to seawater for 4 years and having antifouling ability of Cu2O. For these purposes, energy dispersion of X-ray analysis (EDXA) is employed. It is found that aluminum brass suffer general and pitting corrosion. In most cases, Efird's hypothesis about the antifouling ability of Cu2O is correct. However, the fouling and antifouling behaviors of Cu alloys might be more complex. After barnacles are placed on the specimen surface, localized corrosion takes place between the barnacles and the metal surface. Results suggest that localized corrosion is caused by marine organisms. Among domestic Cu alloys exposed to seawater at four Chinese marine test stations, aluminum brass has good corrosion resistance but high antifouling susceptibility due to the formation of a dense surface film of Cu2O that also contains large amounts of AI and Zn.