刘斌
,
张杰
,
张涛
,
邵亚薇
,
孟国哲
,
王福会
腐蚀学报（英文）
利用电化学测量方法测量纯镍在3.5% NaCl溶液中,静水压力为0 MPa和8 MPa条件下的点蚀击破电位和孕育时间.分析得到纯镍在不同静水压力下点蚀击破电位的理论精确值,利用随机分析方法分析纯镍在静水压力下的点蚀机制.实验结果表明静水压力对纯镍的点蚀过程有着重要的影响,在静水压力下纯镍的点蚀行为和机制发生了改变.在较高的静水压力下,纯镍点蚀产生的敏感性增强,点蚀击破电位Ecritical明显降低；纯镍点蚀诱导时间也变短,其点蚀产生的机制发生了改变；在较高静水压力下,纯镍表面的钝化膜活性增强,恶化了纯镍的耐蚀能力.
关键词:
静水压力
,
nickel
,
deep ocean
,
itting
,
stochastic analysis
李健张涛孟国哲邵亚薇王福会
中国腐蚀与防护学报
通过恒电位的方法测量了在有无磁场条件下纯镁的电流-时间响应曲线，并用随机的方法对结果进行分析，研究了磁场对纯镁点蚀产生过程和点蚀成长概率的影响。磁场通过洛仑兹力产生磁流体动力学效应（Magnetohydrodynamic），显著地增加了纯Mg的点蚀敏感性：对于点蚀的产生过程，磁场的存在改变了纯镁的点蚀产生机制。在无磁场作用的条件下，纯镁的点蚀产生过程都遵循“生死异地”的B1机制；在有磁场作用的条件下，纯镁的点蚀产生过程都遵循“相同点蚀并联”的A3机制。磁场不仅增大了点蚀产生速度，而且降低了点蚀的再钝化速度。对于点蚀的成长过程，磁场提高了稳态点蚀的成长概率，更容易成长为较大的点蚀坑。
关键词:
纯镁
,
pitting
,
magnetic field
,
stochastic analysis
S.L. Zhu
金属学报(英文版)
The stochastic cracking and healing behaviors of reaction-diffusion growth of thin filmswere studied by means of Markov processes analysis. We chose the thermal growth ofoxide scales on metals as an example of reaction-diffusion growth. The thermal growthof oxide films follows power law when no cracking occurs. Our results showed that thegrowth kinetics under stochastic cracking and healing conditions was different fromthat without cracking. It might be altered to either pseudo-linear or pseudo-power lawsdependent upon the intensity and frequency of the cracking of the films. When thehoping items dominated, the growth followed pseudo-linear law; when the diffusionalitems dominated, it followed pseudo-power law with the exponentials lower than theintrinsical values. The numerical results were in good agreement with the meassuredkinetics of isothermal and cyclic oxidation of NiAl-0.1 Y (at. %) alloys in air at 1273K.
关键词:
stochastic analysis
,
null
,
null
刘斌
,
张杰
,
张涛
,
邵亚薇
,
孟国哲
,
王福会
腐蚀学报（英文）
利用电化学测量方法测量纯镍在3.5%NaCl溶液中,静水压力为0 MPa和8 MPa条件下的点蚀击破电位和孕育时间.分析得到纯镍在不同静水压力下点蚀击破电位的理论精确值,利用随机分析方法分析纯镍在静水压力下的点蚀机制.实验结果表明静水压力对纯镍的点蚀过程有着重要的影响,在静水压力下纯镍的点蚀行为和机制发生了改变.在较高的静水压力下,纯镍点蚀产生的敏感性增强,点蚀击破电位E_(critical)明显降低;纯镍点蚀诱导时间也变短,其点蚀产生的机制发生了改变;在较高静水压力下,纯镍表面的钝化膜活性增强,恶化了纯镍的耐蚀能力.
关键词:
静水压力
,
纯镍
,
深海
,
点蚀
,
随机分析
J.Q. Zhang
金属学报(英文版)
Spontaneous electrochemical noise (EN) can be a rich source of information concerning the processes simultaneously occurring on a corroding interface. But the noise signal is often difficult to be analyzed due to the complicated nature of the specific systems being investigated. In this paper, the potential noise fluctuations during the free corrosion of commercial aluminum alloy LY12 in sodium chloride solution was recorded and analyzed with different techniques. The typical results showed that the fractal dimension (D,n) obtained from spectral power density (SPD) is mainly directly proportional to the intensity of pitting corrosion and to the value of pitting parameter (SE) derived from dimensional analysis, while the fractal dimension (DE) obtained from EIS is mainly related to the uniform corrosion.
关键词:
electrochemical noise
,
null
,
null
,
null
,
null
