NaCl水溶液中缓蚀剂控制电偶腐蚀的研究

INHIBITION OF GALVANIC CORROSION BY INHIBITOR IN AQUEOUS NaCl SOLUTION

用电化学方法和原子力显微镜及红外光谱分析技术研究了阳离子缓蚀剂(咪唑啉衍生物)在电偶电极上的吸附行为及其对电偶腐蚀的抑制作用。结果表明,在NaCl水溶液中,缓蚀剂只吸附在碳钢表面,而不吸附在不锈钢表面;当碳钢与不锈钢耦合后,缓蚀剂在偶对的阴极(不锈钢)和阳极(碳钢)都有吸附。缓蚀剂在偶对阳极(碳钢)上的覆盖度小于在单独碳钢上的覆盖度,并且缓蚀剂与前者表面的结合力也有所降低。电偶对中碳钢的腐蚀归因于缓蚀剂的覆盖度与结合力减小的双重因素。

The adsorption behavior of imidazoline derivative as a cationic inhibitor for inhibiting galvanic corrosion has been investigated by using electrochemical methods, atomic force microscopy （AFM） and Fourier transform infrared spectroscopy （FTIR） technology. The results show that the inhibitor adsorbs on the surface of carbon steel while it does not adsorb on the surface of stainless steel in aqueous NaCI solution. When the two metals are electrically coupled in NaCI solution, the inhibitor can adsorb to the surface of both carbon steel and stainless steel. However, in this case, the surface coverage of the inhibitor film formed on the carbon steel decreases compared with that on the surface of single carbon steel immersed in the same electrolyte, and the adsorbability of the inhibitor on the surface of carbon steel is weakened. The corrosion failure for carbon steel of the couple attributes to the decreases of both coverage and adorability of the inhibitor adsorbed on the metal surface.