稀土Ce和La对碳钢在NaCl溶液中的缓蚀机理  

INHIBITIVE CORROSION MECHANISM OF Ce-ION AND La-ION FOR CARBON STEEL IN NaCl SOLUTION

作　　者：汪兵[1] 刘清友[1] 王向东[1] 贾书君[1] 卢吉[1] 董瀚[1] 

机构地区：[1]钢铁研究总院结构材料研究所,北京100081

出　　处：《中国腐蚀与防护学报》2007年第3期151-155,共5页Journal of Chinese Society For Corrosion and Protection

基　　金：973国家重点基础研究项目"提高钢铁材料质量和使用寿命的冶金学基础研究"资助项目(2004cb619101)

摘　　要：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NaCl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 effect of Ce - ion and La - ion inhibiting the corrosion of steel in NaC1 solution has been investigated by salt water droplet test, corrosion production micro - analysis and electrochemical test. The potential - pH diagram of RE - H20 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 cathodic area where the pH value was relatively high and inhibited the corrosion of steel by blocking the transmission of 02 and electron between the cathodic area and solution. The potential - pH diagram and thermodynamics calculation showed the compound of Ce was more stable than compound of La in the acid solution and suggested that the ability of inhibiting corrosion of Ce - ion is better than that of La - ion.

关 键 词：稀土 缓蚀剂 阴极沉淀 电位-PH图 

分 类 号：TG174.42[金属学及工艺—金属表面处理]