STUDY OF THE X70 PIPELINE STEEL CORRODING IN 3.0wt% NaCl SOLUTION USING ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY TECHNIQUE

查看全文 作　　者：[1]L.J.Zhang;[1]Z.Zhang;[1]F.H.Cao;[2]J.Q.Zhang;[1]J.M.Wang;[2]C.N.Cao 机构地区：[1]DepartmentofChemistry,ZhejiangUniversity,Hangzhou310027,China;[2]DepartmentofChemistry,ZhejiangUniversity,Hangzhou310027,China// StateKeyLaboratoryforCorrosionandProtectionofMetals,InstituteofMetalResearch,TheChineseAcademyofSciences,Slaenyang110016,China 出　　处：《Acta Metallurgica Sinica(English Letters)》索引2004年第17卷第6期,共5页 基　　金：the National Key Basic Research Foundation of China(No.G19990650);the National Natural Science Foundation of China(No.50071054). 摘　　要：The corrosion process of the X70 pipeline steel in 3.0wt% NaCl solution were studied using polarization method, and the chronological characteristics during the entire polarization plot were investigated in detail using EIS technique. In the active region of X70 steel, such as 20mV potential bias applied on open circuit potential (OCP), the impedance spectra was comprised of three parts: a high-frequency capacitive loop, a middle-frequency capacitive loop and a low-frequency inductive component. When positive polarization potential increased, the capacitive loops at high and middle frequency range merged, and the inductive component at low frequency shrunk. At high positive polarization potential bias (500-800mV vs. OCP), the high-frequency capacitive loop and the low-frequency inductive loop exhibited as disheveled points due to the synergism of the inhomogeneity of the corroding material and the localized corrosion. The results were fitted utilizing the equivalent circuits to simulate the impedance spectra and to interpret the electrochemical features shown during the experiments. 关 键 词：X70管道钢 腐蚀处理 极化势能 电化学阻抗光谱学 西气东输工程