摘要
研究了炉前材料20G成膜条件下在模拟加氧水（OT）工况和还原性全挥发处理（AVT（R））工况高温水溶液中的电化学行为。用SEM,EDS和XRD对腐蚀产物膜的表面形貌和成分进行表征。结果表明：在40~140℃范围内,20G在OT工况中的腐蚀电流密度随着温度的升高而增加,EIS低频区有Warburg阻抗,电极反应属于混合控制;在AVT（R）溶液中腐蚀电流随着温度的升高先增大后减小;EIS高频区的容抗弧半径随着温度的升高在120℃出现最小值。XRD分析表明,材料表面形成了微米级腐蚀产物膜层,其主要成分为Fe3O4。
Electrochemical corrosion behavior of steel 20G used in boiler-front system was studied by means of a series of electrochemical measurements in simulated high temperature waters, which reproduced the situation of chemical conversion film formation by both the oxygenated treatment （OT） and all volatile treatment （reduction） （AVT（R））. The surface of the test steel was character- ized by scanning electron microscopy （SEM）, energy dispersive spectrometer （EDS）, and X-ray dif- fraction （XRD）. The results show that, when the temperature is between 40 to 140 ℃, the corrosion current density of 20G rises in the OT waters, EIS has the Warburg impedance in low frequency re- gion. While the corrosion current first rises and then decreases in the AVT（R） waters with the in- crease of temperature, while capacitive reactance impedance radius in the high frequency region of EIS spectra presents a minimum value at 120 ℃ with the increase of temperature. The analysis of XRD shows that the surface of the steel forms a passivation film consisted mainlv of Fe3O4.
出处
《中国腐蚀与防护学报》
CAS
CSCD
北大核心
2015年第4期365-371,共7页
Journal of Chinese Society For Corrosion and Protection
基金
湖南省自然科学基金项目(09JJ6067)
湖南省科技攻关项目(2010GK3171)资助
关键词
20G
极化曲线
腐蚀电流
电化学阻抗
20G； polarization curve； corrosion current； electrochemical impedance spectroscopy
