在硫酸盐溶液中使用热运动图来研究铁被动化和转移性行为的机制性研究
Mohammad Amin Razmjoo Khollari1, Kashif Mairaj Deen1, Edouard Asselin1
1Department of Materials Engineering, The University of British Columbia, Vancouver, V6T 1Z4 BC Canada.
概括
热运动图 (TK) 显示了硫酸盐如何影响铁的被动性. 硫酸盐延迟铁的被动化,增加电流密度,影响水性环境中的耐腐蚀性.
科学领域:
- 材料科学 材料科学 材料科学
- 电化学 电化学 电化学
- 腐蚀科学 腐蚀科学
背景情况:
- 了解铁的溶解和被动化对于提高耐腐蚀性至关重要.
- 水性环境对铁的稳定性和应用提出了挑战.
研究的目的:
- 构建和分析脱气溶液中铁的热运动图 (TK).
- 为了研究硫酸 (Na2SO4) 度对铁被动化的影响.
- 阐明硫酸盐离子影响铁腐蚀行为的机制.
主要方法:
- 将潜在动力学极化数据与热力学E-pH图集成,以创建TK图.
- 使用静电 (GS) 极化和电化学阻抗光谱学 (EIS) 的实验验证.
- 使用X射线光电子光谱 (XPS) 进行表面分析以表征被动薄膜.
主要成果:
- 在没有Na2SO4的溶液中,铁在pH 7以上被动,最小电流密度在pH 8时.
- 添加0.1 M Na2SO4会延迟被动化到pH 12并使被动电流密度增加十倍.
- 在XPS分析中,根据pH值和硫酸盐的存在,发现了不同的氧化铁/氧化水化合物组成 (FeOOH/Fe2O3,Fe3O4/Fe2O3).
结论:
- TK图表有效地映射出水溶液中的铁腐蚀行为.
- 硫酸盐离子通过延迟被动化和增加腐蚀速率,显著损害铁的被动性.
- 这些发现为防止硫酸盐含有硫酸盐的环境中的铁腐蚀提供了洞察力.
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