盐湖地区暴露25个月的碳钢表面锈层分析

通过扫描电镜(SEM)、电子探针(EPMA)、X射线衍射(XRD)、红外光谱(IRS)和电化学测试技术分析了碳钢在盐湖大气环境下暴露25个月后上下表面的锈层特征. 结果表明, 碳钢上下表面腐蚀量相似, 锈层中均富有Cl、Mg和Si等外来元素. 两个表面的腐蚀产物都主要由β-FeOOH、Fe8(O,OH)16Cl1.3和少量的γ-FeOOH组成, 最外部分的锈层中还检测到Fe3O4和δ-FeOOH. 电化学测试结果表明, 锈层对基体腐蚀具有抑制作用, 锈层保护性随暴露时间增加而增加.

Analysis on the Corrosion Rust of Carbon Steel Exposed to Salt Lake Area for 2S Months

The rust layers formed on upward and downward surfaces of carbon steel exposed to salt lake atmosphere for 25 months were investigated by scanning electron microscopy (SEM), electron probe micro analyzer (EPMA), X-ray diffraction (XRD), infrared transmission spectroscopy (IRS), and electrochemical techniques. The depths of rust layers on upward and downward surfaces were similar to each other. The corrosion products on the two surfaces were mainly composed of β-FeOOH, Fe8(O,OH)16Cl1.3, and a little γ-FeOOH. δ-FeOOH and Fe3O4 were only detected in outer part of the rust layers. The results of electrochemical analysis showed that the rust layer suppressed the corrosion of steel substrate and the corrosion resistance of rust layers increased with time.