AH32长尺试样在模拟海洋潮差区腐蚀行为的电偶电流研究

发布时间：2018-04-02 08:10

本文选题：AH钢　切入点：潮差区　出处：《金属学报》2017年11期

【摘要】：利用自制的模拟实验装置模拟实海潮差,监测了在模拟潮差区内AH32长尺试样的电偶电流和电极电位变化情况。结果表明,由于供氧差异形成的宏电池作用,AH32长尺试样在潮差区和全浸区内的电极电位分布不均衡,引发了内部的电偶电流,其实质为阴、阳极反应产生的净电流。在潮差区内,AH32长尺试样不同部位的电偶电流随潮位运动发生周期性变化;当潮位最高时,所有部位的电偶电流均处于极大值状态,且中间潮位部位的电偶电流最大,由此所引起的阳极电流也最大。根据电偶电流的变化计算出的干燥、润湿和浸没状态的时间分布表明,AH32长尺试样在潮位区不同部位的腐蚀量取决于润湿和浸没时间在该部位的分配。各部位在浸没态时存在宏电池作用,产生电偶电流。而在润湿态下,由于薄液膜的溶液电阻很大,导致宏电池驱动电位几乎等于在薄液膜上的电压降,因此宏电池作用极弱,且不产生电偶电流。润湿时间和润湿电量的关系显示,潮位运动中AH32长尺试样的最大润湿时间出现在平均中潮位以上的部位,表明因润湿引起的该部位的腐蚀失重最大。结合由浸没态引起的平均中潮位腐蚀失重最大的结果可以确定,在潮水涨落过程中AH32长尺试样的最大腐蚀失重量应出现在平均中潮位偏上的部位,这与腐蚀速率的测量结果一致。
[Abstract]:The electric coupling current and electrode potential of AH32 long scale sample in the simulated tidal range were monitored by using a self-made simulation experiment device. The results show that the electric current and electrode potential of the AH32 long scale sample in the simulated tidal range are measured. Due to oxygen supply difference, the electrode potential distribution of AH32 long ruler sample is unbalanced in the tidal range and the whole immersion zone, which leads to the internal galvanic current, which is essentially negative. The net current produced by anodic reaction. The coupling current of AH32 long ruler specimen changes periodically with the tide level movement in the range of tidal difference. When the tide level is highest, the coupling current of all parts is in the state of maximum value. The coupling current at the middle tide level is the largest, and the anode current caused by it is also the largest. The time distribution of wetting and immersion states indicates that the corrosion amount of AH32 specimen in different parts of tidal zone depends on the distribution of wetting and immersion time in this part. In the wet state, however, because the solution resistance of the thin liquid film is very large, the driving potential of the macro cell is almost equal to the voltage drop on the thin liquid film, so the action of the macro cell is extremely weak. The relation between wetting time and wetting quantity shows that the maximum wetting time of AH32 long scale specimen appears in the position above the average middle tide level in tidal level movement. The results show that the corrosion weight loss of this part is the largest due to wetting. Combined with the results of the maximum corrosion loss at the average mid-tidal level caused by immersion, it can be determined that, In the process of tidal fluctuation, the maximum corrosion weight loss of AH32 long scale specimen should appear in the position above the average middle tide level, which is consistent with the result of corrosion rate measurement.
【作者单位】：中国科学院金属研究所;
【基金】：国家自然科学基金项目No.51671200 国家高技术研究发展计划项目No.2015AA034301 国家腐蚀平台基金中国科学院海洋研究所海洋环境腐蚀与生物污损重点实验室资助项目No.MCKF201611~~
【分类号】：TG172.5

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