Corrosion Characteristics of Galvanized Flat Steel for Power Grounding in NaCl Solution Medium
- 2011年第17卷 
应用极化曲线、电化学阻抗谱和中性盐雾腐蚀试验法，研究电力接地材料镀锌扁钢在5%NaCl溶液中的腐蚀行为，用SEM、XRD观察与表征镀锌扁钢样品腐蚀的表面形貌及其产物性质. 结果表明，在20~60 ℃温度范围内，镀锌扁钢腐蚀电流随温度升高而增大，60 ℃时腐蚀速率达到0.8408 mA•cm-2（是20 ℃腐蚀速率的2.9倍）；延长腐蚀过程至60 d时样品腐蚀速率达到最大值（1.95 mg•cm-2•d-1），而后有下降趋势；在盐雾腐蚀过程中，扁钢的镀锌层先发生孔蚀，其后少量孔蚀变为坑蚀，其中白锈腐蚀产物为ZnO和Zn5(OH)8Cl2•H2O，红锈腐蚀产物为Fe+3OOH和Fe3O4，并混有少量的Zn5(OH)8Cl2•H2O.The corrosion behavior of power grounding galvanized flat steel was studied by polarization measurement, electrochemical impedance spectroscopy and neutral salt spray test in 5% NaCl solutions. The surface morphologies of galvanized coating and structural properties of corrosion products were observed with scanning electron microscope and X-ray diffraction spectrometer, respectively. Results showed that under the temperatures of 20~60℃, the corrosion currents of galvanized flat steel increased with the temperature rising. The corrosion rate at 60℃ was 0.8408 mA?cm-2, which is 2.9 times larger than that at 20℃. The corrosion rate dropped after reaching the maximal value of 1.95 mg?cm-2?d-1 when the exposure time was 60 d. The major corrosion form of galvanized coating was pitting corrosion, then some corrosion pits was converted into etch pits. Main corrosion products of white rust were ZnO and Zn5(OH)8Cl2?H2O, while those of red rust were Fe+3OOH and Fe3O4 with a small amount of Zn5(OH)8Cl2?H2O being also detected.