The electrochemical corrosion behavior of X80 carbon steel was investigated in a supercritical CO (sCO) environment at 60 ℃ and 9 MPa, by in-situ experiments and density functional theory (DFT) calculations, revealing the corrosion mechanism. For in situ electrochemical measurements, two novel CO-rich and HO-rich cells were developed to replace the traditional three-electrode cell. Electrochemical impedance spectroscopy revealed distinct differences in the corrosion behavior between CO-rich and HO-rich environments during the later stages of testing. In HO-rich environments, as corrosion time increased, the corrosion product layer gradually changed from porous to dense, eventually forming a protective layer. In CO-rich environments, corrosion occurs mainly in areas where water condenses to form FeCO. Simultaneously, microscopic calculations provided evidence for the three-step sCO hydrolysis mechanism and the formation of FeCO products.

中文翻译：

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X80碳钢在管道中的超临界CO2腐蚀行为研究：原位实验和DFT研究


通过原位实验和密度泛函理论（DFT）计算，研究了X80碳钢在60℃、9MPa超临界CO（sCO）环境中的电化学腐蚀行为，揭示了腐蚀机理。对于原位电化学测量，开发了两种新型的富含 CO 和 H2O 的电池来替代传统的三电极电池。电化学阻抗谱揭示了在测试的后期阶段，富含CO和富含H2O的环境之间的腐蚀行为存在明显差异。在富含H2O的环境中，随着腐蚀时间的增加，腐蚀产物层逐渐从多孔变为致密，最终形成保护层。在富含 CO 的环境中，腐蚀主要发生在水凝结形成 FeCO 的区域。同时，微观计算为三步sCO水解机理和FeCO产物的形成提供了证据。