LAUSR

ABSTRACT The microbial corrosion behaviour of nickel-phosphorus (Ni-P) by Desulfovibrio desulfuricans (SRB, ATCC 7757) was investigated experimentally. The colonization of SRB on Ni-P surface was observed by fluorescence microscope (FM) and scanning electron microscope (SEM). The corrosion of Ni-P plating was studied by electrochemical impedance spectroscopy (EIS). The results indicate corrosion aggravated from 1 d to 7 d and then slowed down after 7 d. The corrosion products were analyzed by Energy Dispersive X-ray (EDX) spectra. The corrosion of Ni-P in SRB medium was more deteriorative than the control group. Accordingly, the corrosion process was accelerated in the presence of SRB and its extracellular polymeric substance (EPS). The EIS data of Ni-P plating were fitted to equivalent circuits. The results show that the resistance of charge transfer on Ni-P surface increased quickly from 1 d to 7 d and then decreased to 22.4 kΩ·cm−2 finally.