Effects of Bivalent Cations on Corrosion Inhibition of Steel by 1‐Hydroxyethane‐1,1‐diphosphonic Acid
Effects of Bivalent Cations on Corrosion Inhibition of Steel by 1‐Hydroxyethane‐1,1‐diphosphonic Acid
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DOI：
10.1149/1.1391706
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发表时间：
1999-03
影响因子：
3.9
通讯作者：
I. Felhősi;Z. Keresztes;F. Kármán;M. Mohai;I. Bertóti;E. Kálmán
中科院分区：
文献类型：
--
作者：
I. Felhősi;Z. Keresztes;F. Kármán;M. Mohai;I. Bertóti;E. Kálmán
采用电化学技术、X射线光电子能谱和原子力显微镜研究了钙、锌离子对1-羟基乙烷-1，1-二膦酸（HEDP）缓蚀作用的影响。钙、锌离子的加入以协同作用的方式显著提高HEDP的缓蚀效率。当Ca/HEDP摩尔比为0.5，Zn/HEDP摩尔比为3时，HEDP的缓蚀效果最好。在这些添加剂的存在下的缓蚀机理被证明是不同于单独与HEDP，并与HEDP和阳离子添加剂之间形成不同的络合物物种。所研究的系统的频率响应描述的传递函数包含两个弛豫时间常数对应的电荷转移过程和多孔氧化物层。XPS测量结果支持，通过增加溶液中的锌浓度（在Zn/HEDP = 0.5-3的范围内），可以实现抑制剂层中更高的锌和磷含量以及O-Fe和HO-Fe比的连续变化。化学结构的变化建立在氧化物-氢氧化物层自发开发的钢表面上。抑制剂化合物的协同效应也出现在表面形态中，导致光滑的发展，即，原子力显微镜显示的致密保护层。
The influence of calcium and zinc ions on the corrosion inhibition effect of 1-hydroxyethane-1,1-diphosphonic acid (HEDP) on carbon steel has been investigated by electrochemical techniques, X-ray photoelectron spectroscopy, and atomic force microscopy. Addition of calcium or zinc ions greatly increased the inhibition efficiency of HEDP in a synergistic manner. The highest inhibition effect was obtained for molar ratios of Ca/HEDP = 0.5 and Zn/HEDP = 3 for 3 X 10 -4 mol dm -3 HEDP. The corrosion inhibition mechanism in the presence of these additives proved to be different from that with HEDP alone and was related to the formation of different complex species between HEDP and cation additives. The frequency response of the studied system was described by a transfer function containing two relaxation time constants corresponding to the charge-transfer process and the porous oxide layer. Higher zinc and phosphorous content in the inhibitor layer and a continuous change in the O-Fe and HO-Fe ratio were achieved by increasing zinc concentration in the solution (in the range Zn/HEDP = 0.5-3) as supported by XPS measurements. Changes in the chemical structure were established in the oxide-hydroxide layer developed spontaneously on the steel surface. The synergistic effect of inhibitor compounds appeared also in surface morphology, leading to the development of smooth, i.e., dense, protective layers as revealed by atomic force microscopy.