稀土铈和镧对碳钢在氯化钠溶液中缓蚀机理的研究

采用盐水滴腐蚀试验、腐蚀产物SEM及XPS分析、极化曲线测试分别研究了Ce3+和La3+对碳钢在氯化钠溶液中的缓蚀机理，并利用热力学数据绘制了Ce-H2O及La-H2O二元电位－pH相图。结果表明Ce3+和La3+能够在pH值较高的阴极区沉淀，阻碍O及电子在碳钢表面和溶液之间的转移和传递，通过抑制阴极反应从而减缓腐蚀的进行。热力学计算及电位 － pH图表明Ce3+在有氧时可被氧化成沉淀倾向更强的Ce4+，在酸性溶液中Ce4+化合物的稳定性要高于La3+化合物，因此Ce3+的缓蚀效果要好于La3+。

The Study of Inhibitive Corrosion Mechanism of Ce-ion and La-ion for Carbon Steel In NaCl Solution

The effect of Ce-ion and La-ion inhibiting the corrosion of steel in NaCl solution has been investigated by salt water droplet test, corrosion production micro-analysis and electrochemistry test. The potential-pH diagram of RE-H2O was also used to investigate the chemical stability of various kinds of RE compound. The results showed that oxide and hydrate of RE deposited in the cathodal area where the pH value was relatively high and inhibited the corrosion of steel by blocking the transmission of O2 and electron between the cathodal area and solution. The potential-pH diagram and thermodynamics calculation showed the compound of Ce was more stable than compound of la in theacid solution and suggested that the ability of inhibition corrosion of Ce-ion is better than that of la-ion.