腐蚀电化学 2

in cn-stem •  2 months ago  (edited)

继续整理一下电化学吧。

上一帖子基本上简单说了一下腐蚀电化学的基本要素和分类,这一节简单说一下过程。


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热力学,一个金属发生电化学腐蚀的倾向。。。电化学的主要发生的主要动力(driving force)就是电位差,简单来说就是电压。阴极和阳极之间如果有电压,就会产生电子的流动,电子在金属溶液表面流动的方式就是电化学的电极反应。每个电极反应是分开发生在电极上的,组合起来就是一个完整的反应。不同金属在不同环境下会产生不同的电位,可以通过标准点位表(galvanic series)查询 [1]。在非标准条件下,电极的点位可以通过能斯特方程(Nernst equation)来计算[2]。

动力学, 热力学表示的是腐蚀发生的倾向,动力学表示发生的速度。有可能倾向较大,但是速度较慢。动力学有更多的影响因素,一般来说,电化学的反应的初期都是比较快速的,然后电极点位会随着反应的进行变动,这种点位变动从称之为极化。主要的极化方式有动力极化(Activation polarization),浓差极化(concentration polarization)和电阻极化 [3]。极化之后,还有钝化,有些金属虽然腐蚀倾向较大,但是很容易生成一种钝化膜来保护金属基体(铝),这种反应其实也是一种变相的极化保护了金属本身。另外的极化保护可以是管道的阴极保护。

好了,又罗嗦了一些估计没人在意的东西,加了参考文献,希望大家开心。

[1] https://en.wikipedia.org/wiki/Galvanic_series
[2] https://en.wikipedia.org/wiki/Nernst_equation
[3] https://en.wikipedia.org/wiki/Polarization

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@tipu curate

感谢代理152.06SP 给team-cn! 由于你使用CN作为你的标签,额外获得1%点赞! 你的帖子获得team-cn 9% 点赞!(如果不想看到这个回复,请回复“取消”)

You have received a 0.31% upvote based on your stake of 172.94628138 UFM!

你那里天气如何?想一展歌喉吗?好声音@cn-voice欢迎你~倘若你想让我隐形,请回复“取消”。

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