800合金在300℃NaOH和ETA溶液中的腐蚀行为  

CORROSION BEHAVIOR OF ALLOY 800 IN Na OH AND ETA SOLUTIONS AT 300 ℃

作　　者：王家贞[1] 王俭秋[1] 韩恩厚[1] 

机构地区：[1]中国科学院金属研究所中国科学院核用材料与安全评价重点实验室,沈阳110016

出　　处：《金属学报》2016年第5期599-606,共8页Acta Metallurgica Sinica

基　　金：国家科技重大专项项目2011ZX06004-009;国家重点基础研究发展计划项目2011CB610500资助~~

摘　　要：采用动电位极化曲线,电化学阻抗谱(EIS),SEM,XPS等分析手段研究了800合金在300℃Na OH和乙醇胺(ETA)溶液中的腐蚀行为.结果表明,ETA的添加降低合金的腐蚀电流密度,增大了氧化膜的膜层电阻.无论是否添加ETA,800合金均为双层膜结构.未添加ETA时,合金氧化膜外层富Ni,ETA添加后氧化膜外层富Cr.ETA的添加提高了氧化膜中Cr的富集程度,促进了铬氧化物的形成,增强了800合金氧化膜的保护性.Many components in secondary side of pressurized water reactors（PWRs） are made of carbon steels and low alloy steels. The corrosion products produced by the flow accelerated corrosion（FAC） of these components can deposite on the surface of steam generator（SG） tubes and decrease the heat transfer efficiency of SG tubes. Moreover, the enrichment of foreign ions（e.g. Cl-and Pb2＋） occurs with the sedimentation of corrosion products and causes the local environment degradation, and thus accelerates the failure of SG tubes. In order to decrease the FAC of carbon steels and low alloy steels, p H controllers are often added to adjust the p H value of secondary water. The water chemistry environment of secondary side in PWRs has experienced various treatment techniques, such as phosphate treatment, all volatile treatment（AVT）, morpholine（MPH） treatment, ethanolamine（ETA） treatment, and boric acid treatment. In comparision with AVT, ETA can significantly reduce the concentration of Fe in the steam-water phase region and water supply system because of its higher alkalinity and lower molar concentration in feedwater. Due to the high resistance to corrosion and stress corrosion cracking in high temperature and high pressure water, alloy 800 is often used as steam generator tubes in nuclear power plants and thus becomes increasingly attractive among researchers. However, few studies focus on the effect of ETA on the corrosion behavior of alloy 800 in high temperature and high pressure water. This work mainly aims to investigate the corrosion behavior of alloy 800 in Na OH and ETA solutions at 300 ℃ by potentiodynamic polarization curve, electrochemical impedance spectra（EIS）, SEM and XPS. The electrochemical results demonstrate that the addition of ETA decreases the current density of anodic and cathodic reactions, and increases the corrosion potential of alloy800. Besides, ETA addition significantly increases the resistance of inner oxide layer and makes the oxide film more compact, which i

关 键 词：800合金 乙醇胺 动电位极化曲线 氧化膜 

分 类 号：TG172.9[金属学及工艺—金属表面处理]