In this work, the corrosion process of Fe-Cr alloys in flowing CO was simulated using molecular dynamics within an extended ReaxFF force field. The effects of Cr content, temperature variations, impurity gases and vacancy defects were discussed. The corrosion process was dominated by oxidation and carburization reactions, with the oxidation rate higher than carburization rate, resulting in the formation of a carbide layer within the central region between two oxide layers. The increase in Cr content tended to decelerate corrosion, while raising temperature aggravated the corrosion of Fe-Cr alloy. The presence of O and SO impurities was found to thicken the corrosion layer, in contrast to the effects of CO and HO impurities. A notable finding highlighted the positive influence of 2% vacancy defects in enhancing the corrosion resistance of the Fe-Cr alloy. The AlO coating achieved a good corrosion protection by inhibiting the dissociation of CO.

中文翻译：

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超临界 CO2 环境中 Fe-Cr 合金腐蚀行为的原子洞察

在这项工作中，利用扩展的 ReaxFF 力场内的分子动力学模拟了流动 CO 中 Fe-Cr 合金的腐蚀过程。讨论了Cr含量、温度变化、杂质气体和空位缺陷的影响。腐蚀过程以氧化和渗碳反应为主，氧化速率高于渗碳速率，导致在两层氧化层之间的中心区域形成碳化物层。 Cr含量的增加有减缓腐蚀的趋势，而升高温度则加剧Fe-Cr合金的腐蚀。研究发现，与 CO 和 H2O 杂质的影响相比，O 和 SO 杂质的存在会增厚腐蚀层。一项值得注意的发现强调了 2% 空位缺陷对提高 Fe-Cr 合金耐腐蚀性能的积极影响。 Al2O3涂层通过抑制CO的解离而实现良好的腐蚀防护。