关键词: 化学镀Ni-Cu-P, 微生物污垢, 腐蚀, 电化学, 生物膜

Abstract: The low-carbon steel which is commonly used in the heat exchangers was modified using the method of electroless Ni-Cu-P. The fouling characteristics of iron bacteria on the surface of electroless plating of Ni-Cu-P were studied. A five-days fouling deposition experiments were carried out in iron bacteria suspension. The weights of the fouling deposition,the corrosion on the modified surface and the iron bacteria counts were recorded. The surface microstructure of electroless plating of Ni-Cu-P was analyzed. The samples were tested by means of the polarization curves and the electrochemical impedance spectroscopy,the changing rule of the polarization curves and the electrochemical impedance spectroscopy were analyzed. The best equivalent circuit was fitted using ZsimpWin method. The experimental results show that the Ni-Cu-P plating could effectively inhibit the growth of microorganisms. Compared with the plain low-carbon steel,it is found that the fouling deposition decreased by 89.1% and the weight loss resulting from corrosion decreased by 80.2%. Corrosion potential of the electroless Ni-Cu-P plating was higher than that of the low carbon steel. The corrosion current density was smaller than that of the low carbon steel. The capacitive are radius was greater than that of the low carbon steel. The corrosion rate of the electroless Ni-Cu-P plating decreased at the beginning,then increased,and reached the minimum at 12 hours.

Key words: electroless Ni-Cu-P, microbial fouling, corrosion, electrochemistry, biofilm