Research of microorganism corrosion properties of 2024-T31 aluminum-magnesium alloy in oil-water system

Abstract

The surface analysis techniques and chemical technical means (polarization curves and AC impedance technique) were applied to research the corrosion characteristics of microorganisms SRB of 2024-T31 aluminum-magnesium alloy in the oil-water system, and the corrosion mechanism was finally analyzed. The results showed that SRB accelerate the corrosion process and cause uneven pitting on the surface of the metal matrix. Passive and biological films control the corrosion of the metal substrate in bacterial oil-water system. In the initial stage of immersion, a loose and uneven biofilm formed on the surface of substrate which accelerated its corrosion. In the midterm, the effect of biofilm gradually weakened while the protective effect of the passive film grew more insistently; the rate of corrosion slowed down. In the later period, localized corrosion cell of large cathode/small anode formed on the surface of the substrate which accelerates the corrosion.