Electrochemical Study On Microbiologically Influenced Corrosion Of Copper Alloy In Seawater Cooling System

Microbiologically influenced corrosion (MIC) is a serious problem for marine engineering structures. MIC is characterized by that microorganisms attach to the surfaces of metal or alloy, and form biofilms which change corrosive conditions such as dissolved oxygen, pH and chemical species contents within the biofilm, then accelerate corrosion.Natural sea water is essentially a medium with high concentration of salts and large groups of living organisms and is highly corrosive to many metals such as steel, stainless steel, aluminium alloy, copper alloy and nickel alloy. Copper base alloys are used extensively in marine heat exchangers because of their excellent corrosion resistance properties, antifouling properties, machinability and high conductivity.With the development of seawater utilization in china, MIC for marine engineering structures has attracted more and more attention. When seawater is substituted for fresh water as industrial cooling water, with the special engineering structure and circulating condition of seawater cooling system seawater is especially suitable for the growth and propagation of microorganism. Therefore seawater is particularly susceptible to corrosion and biofouling in seawater cooling system.However there are a few literatures relating to the microbiologically influenced corrosion behavior of copper alloy, and no work appears to have been published on MIC attack on copper-zinc alloy in seawater cooling system by electrochemical techniques. Therefore to conduct a systematic study to investigate in detail the characteristics of MIC is necessary. The experimental results indicate that as follows.(1) In the paper the microbiologically influenced corrosion behavior of copper-zinc alloy HSn62 in simulated microbiological environment were studied through electrochemical experiments and surface analysis. For investigating the character and the formation process of the biofilm the open circuit potential, pH value, and polarization resistance (Rp) versus time plots in various simulated...