孟国哲
,
李瑛
,
王福会
中国腐蚀与防护学报
利用磁控溅射技术在玻璃基体上制备了Fe-20Cr纳米晶涂层。分别测试了Fe-20Cr铸态和纳米晶涂层在含氯离子溶液（0.005mol/L H2SO4+0.5mol/L NaCl）与不含氯离子的溶液（0.005mol/L H2SO4+0.25mol/LNa2SO4）中的动电位极化曲线。结果表明,纳米化使材料的溶解速度增大，纳米晶涂层在两种溶液体系中均容易钝化；与铸态合金相比，纳米涂层的维钝电流增大两个数量级。在含氯离子溶液中，纳米晶涂层的维钝区间是铸态合金的两倍,耐局部腐蚀性能得到很大提高。利用电容测试技术和Mott-Schottky关系研究了Fe-20Cr铸态合金与纳米晶涂层分别在两种溶液中所形成钝化膜的半导体性能。结果表明铸态合金在不含氯离子的溶液中低电位下所形成的钝化膜为p型半导体,高电位下形成n型半导体，在含氯离子溶液中形成的钝化膜为p型半导体；而纳米晶涂层在两种溶液体系中形成的钝化膜均为n型半导体。钝化膜的结构类型的不同是导致Fe-20Cr纳米晶涂层与铸态合金具有不同电化学行为的主要原因。
关键词:
磁控溅射
,
nanocrystalline
,
pitting corrosion
,
Mott-Schottky plot
范林
,
李晓刚
,
杜翠薇
,
刘智勇
中国腐蚀与防护学报
采用动电位极化曲线、恒电位极化曲线、电化学阻抗谱(EIS)、Mott-Schottky分析等电化学方法研究了X80管线钢在各种高浓度的NaHCO3溶液中形成钝化膜的电化学行为。结果表明， X80管线钢钝化膜的稳定性和耐蚀性会受到NaHCO3溶液浓度的影响。钝化膜电化学性质随HCO3-浓度升高而降低；内层Fe3O4的厚度不随HCO3-浓度变化，推测其形成与成膜电位有关；内外膜层厚度比随HCO3-浓度的升高而增大，钝化膜的稳定性和耐蚀性主要受外层γ-Fe2O3的影响。根据点缺陷(PDM)理论的分析认为，NaHCO3溶液浓度升高时钝化膜稳定性和耐蚀性的降低与溶液电导率的升高和HCO3-在缺陷点处吸附作用的增强有关。
关键词:
X80管线钢
,
passive film
,
polarization curve
,
EIS
,
Mott-Schottky plot
Dangguo LI
金属学报(英文版)
The chemical composition and semi-conductive properties of passive film on nickel-based alloy (G3 alloy) in bicarbonate/carbonate buffer solution were investigated by Auger spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectra (EIS) and Mott-Schottky plot. AES and XPS results showed that the passive film appeared double-layer, in which the inner film was composed of nickel oxide, the mixed nickel-chromium-molybdenum-manganese oxides were the major component of the outer film. The electrochemical results revealed that the factors including frequency, potential, time, temperature and pH value can affect the semi-conductive property, the doping densities decreased with increasing potential and pH value, prolonging time, and decreasing temperature. According to the above results, it can be concluded that the film protection on the substrate enhanced with increasing potential and pH value, prolonging time, and decreasing temperature.
关键词:
Nickel-based alloy
,
俄歇分析
,
X-射线光电子能谱
,
电化学阻抗谱
,
Mott-Schottky曲线
