摘要
通过电化学试验方法对X70钢在NaHCO3溶液中的腐蚀行为进行了研究。实验结果表明,当NaHCO3质量分数低于0.10%时,极化曲线呈现阳极活化溶解过程,高于0.10%时阳极极化出现钝化过程,并且在-0.6 V(vs.SCE)左右出现了一个新的小电流峰。通过对交流阻抗谱分析发现,高频区均是由略偏离半圆的容抗弧组成,并且实部有所收缩。HCO3-的还原反应在阴极过程中起主要作用,整个过程受极化控制。X70钢在NaHCO3溶液中的腐蚀速度随着NaHCO3质量分数的增大而增大,在试验结束后,对试样表面的腐蚀形貌进行了观察,并利用XRD分析出腐蚀产物主要为FeO(OH)和Fe3O4。
By means of electrochemical experiments, the corrosion behaviors of X70 steel in sodium bicarbonate solution were studied. The results showed that when the concentration of sodium bicarbonate was below 0.15%, polarization curves represented anodic dissolution process; when the concentration was above 0, 15% , polarization curves represented an anodic passivating process. Furthermore there was a new current peak at about -0, 6 V （vs. SCE）. EIS results showed that the high frequency region was generally irregular capacitive impedance, and real part was constricted. The HCO3^- deoxidation reaction played a main role in the cathode process and activation control was the crucial procedure. Through steeping experiment, corrosion rate of X70 steel changed as the concentration of sodium bicarbonate. In the end, the surface of specimen was observed by SEM and the corrosion products analyzed by XRD were mainly FeO （OH） and Fe3O4.
出处
《装备环境工程》
CAS
2007年第3期40-44,共5页
Equipment Environmental Engineering
基金
国家自然科学基金项目(50499333)
国家科技基础条件平台建设项目(2005DKA10400)
