Bojinov Martin, Betova Iva, Ivanova Nikoleta, Karastoyanov Vasil
Department of Physical Chemistry, University of Chemical Technology and Metallurgy, 8 Kliment Ohridski Blvd., 1756 Sofia, Bulgaria.
Institute of Electrochemistry and Energy Systems, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria.
Materials (Basel). 2025 Feb 21;18(5):944. doi: 10.3390/ma18050944.
The erosion-corrosion mechanism of low-alloy steel in high-ammonia steam generator's chemistry is studied by in situ impedance spectroscopy coupled with an in-depth analysis of formed oxides using glow discharge optical emission spectroscopy. A novel electrode setup that ensures turbulent conditions in the vicinity of the steel sample is used. The effect of temperature (130-230 °C) and flow rate (2-10 dm h) is investigated. The energy of adsorption of ammonia depends on temperature and is estimated using molecular dynamic simulations. The kinetic and transport parameters of the corrosion process are estimated via the regression of the experimental impedance spectra to the transfer function of the Mixed-Conduction Model for oxide films. Conclusions are drawn about the effect of Cr in the alloy, and the temperature and flow rate on the corrosion mechanism.
通过原位阻抗谱结合辉光放电光发射光谱对形成的氧化物进行深入分析，研究了低合金钢在高氨蒸汽发生器化学环境中的冲蚀腐蚀机制。使用了一种新型电极装置，以确保钢样品附近的湍流条件。研究了温度（130 - 230°C）和流速（2 - 10 dm h）的影响。氨的吸附能量取决于温度，并通过分子动力学模拟进行估算。通过将实验阻抗谱回归到氧化膜混合传导模型的传递函数来估算腐蚀过程的动力学和传输参数。得出了合金中Cr以及温度和流速对腐蚀机制的影响结论。
