10号碳钢在NaOH溶液中的腐蚀电化学行为  

Electrochemical Corrosion Behavior of 10~# Carbon Steel in NaOH Solution

作　　者：赵天雷 路伟 吕海武 徐光远 王奎升[1] ZHAO Tianlei;LU Wei;LV Haiwu;XU Guangyuan;WANG Kuisheng(Electrical and Mechanical Engineering College,Beijing University of Chemical Technology,Beijing 100029,China;Testing Center,Petrochina Jilin Petrochemical Branch,Jilin 132021,China)

机构地区：[1]北京化工大学机电工程学院,北京100029 [2]中国石油吉林石化分公司检测中心,吉林132021

出　　处：《腐蚀与防护》2018年第11期833-837,842,共6页Corrosion & Protection

摘　　要：采用动电位扫描法和电化学阻抗谱法研究了NaOH溶液的温度和含量对10号碳钢耐蚀性的影响,并通过光学金相显微镜,对试样的表面腐蚀形貌进行了观察。结果表明:随着NaOH溶液温度和浓度的升高,10号碳钢的腐蚀电流密度升高,自腐蚀电位降低,腐蚀程度加深。NaOH质量分数≤20%时,极化曲线有明显的钝化区,电化学阻抗谱Nyquist图呈现单一容抗弧,10号碳钢形成的钝化膜致密完整,腐蚀较轻,试样表面在过钝化区发生点蚀。NaOH质量分数≥30%,温度>30℃时,极化曲线出现阳极电流密度峰,电化学阻抗谱Nyquist图高频区容抗弧半径减小,低频区出现扩散阻抗,反应由电化学控制转为扩散控制,10号碳钢点蚀程度加深。The effect of the temperature and content of NaOH on the corrosion behavior of 10^# carbon steel was studied through potential dynamic method and electrochemical impendance spectroscopy. The surface corrosion morphology of specimens was observed by an optical microscope. The results showed that with the increase of the temperature and content of NaOH solution, the corrosion current density of 10^# carbon steel increased, the corrosion potential decreased, and the corrosion degree increased. When the concentration of NaOH was ≤ 20%, the polarization curves had an evident passivation zone and there was a single capacitive reactance arc on the Nyquist diagrams of electrochemical impedance spectroscopy, the passivation film was complete and dense, the corrosion was relatively light, pitting occured on the surface of 10^# carbon concentration of NaOH was ≥30% and the temperature was steel when it came to transpassivation zone. When the 〉30℃, anodic current density peaks appeared on the polarization curves, the radius of capacitive reactance arc in the high frequency area of Nyquist figure decreased and diffusion impedance occurred in the low frequency area of Nyquist figure, the reaction was controlled by diffusion instead of electrochemistry, the pitting degree of 10^# carbon steel was deepened.

关 键 词：10号碳钢 NAOH 腐蚀 电化学阻抗谱 表面腐蚀形貌 

分 类 号：TG174[金属学及工艺—金属表面处理]