Introductory lecture on corrosion chemistry: a focus on anodic hydrogen evolution on Al and Mg.
Introductory lecture on corrosion chemistry: a focus on anodic hydrogen evolution on Al and Mg.
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DOI：
10.1039/c5fd00066a
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发表时间：
2015-07
影响因子：
3.4
通讯作者：
G. Frankel;S. Fajardo;B. Lynch
中科院分区：
文献类型：
--
作者：
G. Frankel;S. Fajardo;B. Lynch
随着阳极电流密度或电位的增加，溶解镁表面上的析氢速率（HE）增加，这有时被称为负差效应，近年来一直是讨论的主题。本文对这一课题的最新研究成果进行了综述。增加的腐蚀产物层的催化活性，无论是从积累的杂质或从镁羟基氧化物本身，被证明有轻微的影响，在高阳极电流密度和电位溶解镁上观察到的阳极HE。铝在浓盐酸中的阳极极化过程中表现出类似的特性，尽管铝的阳极HE速率小于镁。阳极氢的可能机制和晶间腐蚀和环境开裂领域的影响进行了讨论。
The increase in the rate of hydrogen evolution (HE) on dissolving Mg surfaces with increasing anodic current density or potential, which is sometimes called the negative difference effect, has been the topic of much discussion in recent years. A review of the very recent contributions to this subject is given in this paper. Increased catalytic activity of the corrosion product layer, either from the accumulated impurities or from the Mg oxy-hydroxide itself, is shown to have a minor influence on the anodic HE observed on dissolving Mg at high anodic current densities and potentials. Al exhibits similar characteristics during anodic polarization in concentrated HCl, although the anodic HE rate on Al is less than on Mg. Possible mechanisms for the anodic hydrogen are provided and implications in the area of intergranular corrosion and environmental cracking are discussed.