EFFECT OF TRACE ORGANIC-COMPOUNDS ON THE CORROSION OF CU NI ALLOYS INSULFIDE POLLUTED SEAWATER/

Trace organic complexing agents were investigated to check their abili ty to reduce the relatively high corrosion rates of Cu/Ni alloys in su lfide polluted seawater. It is found that an organic complexing agent such as fuchsin in the concentration range of 5 ppm is an excellent in hibitor against uniform and localized attack for 70/30 Cu/Ni alloy in 2 ppm sulfide polluted seawater. Another metal complexing agent, SSA ( 5-sulfosalicylic acid), was found to be effective for the 90/10 Cu/Ni alloy against enhanced attack by sulfide polluted seawater while it wa s ineffective for 70/30 Cu/Ni alloy. EDTA (ethylene diaminetetraacetic acid disodium salt) was found to be ineffective for both Cu/Ni alloys when used by itself in the concentration range of 5 ppm. A mechanism is proposed to explain the effectiveness of the various selected trace organic complexing agents on the corrosiveness of sulfide polluted se awater.