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

摘要： 利用化学镀Ni-Cu-P工艺对换热器常用材料低碳钢进行改性，研究Ni-Cu-P镀层表面铁细菌污垢特性。将试样置于铁细菌悬液中进行为期5天的污垢沉积实验，记录Ni-Cu-P镀层表面铁细菌污垢沉积量、腐蚀失重量以及铁细菌生长变化情况，分析铁细菌污垢实验前后镀层表面微观形貌。测试不同时间的极化曲线和电化学阻抗谱，定性分析极化曲线和阻抗谱的变化规律，采用ZsimpWin拟合出最佳等效电路模型。研究结果表明，Ni-Cu-P镀层可以有效抑制微生物污垢生长，与未施镀的碳钢试样对比，Ni-Cu-P改性表面污垢沉积量减少89.1%，表面失重量减少80.2%。Ni-Cu-P镀层自腐蚀电位高于碳钢，自腐蚀电流密度比碳钢小，且容抗弧半径大于碳钢，展现了较好的耐蚀性。铁细菌对Ni-Cu-P镀层的腐蚀速度先减小后增大，在12h腐蚀速度最小。

关键词: 化学镀Ni-Cu-P, 微生物污垢, 腐蚀, 电化学, 生物膜