The aim of this work was to study the corrosion behavior of a Fe-Cr-Ni alloy (310 H stainless steel) in water at a supercritical temperature of 550 °C and a pressure of 250 atm for up to 2160 h. At supercritical temperature, water is a highly aggressive environment, and the corrosion of structural materials used in a supercritical water-cooled nuclear reactor (SCWR) is a critical problem. Selecting proper candidate materials is one key issue for the development of SCWRs. After exposure to deaerated supercritical water, the oxides formed on the 310 H SS surface were characterized using a gravimetric analysis, a metallographic analysis, and electrochemical methods. Gravimetric analysis showed that, due to oxidation, all the tested samples gained weight, and oxidation of 310H stainless steel at 550 °C follows parabolic rate, indicating that it is driven by a diffusion process. The data obtained by microscopic metallography concord with those obtained by gravimetric analysis and show that the oxides layer has a growing tendency in time. At the same time, the results obtained by electrochemical impedance spectroscopy (EIS) measurements indicate the best corrosion resistance of Cr, and (Fe, Mn) Cr₂O₄ oxides developed on the samples surface after 2160 h of oxidation. Based on the results obtained, a strong correlation between gravimetric analysis, metallographic analysis, and electrochemical methods was found.

中文翻译：

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奥氏体钢（Fe，Cr和Ni）310 H在脱气超临界水静态系统中的氧化行为

这项工作的目的是研究Fe-Cr-Ni合金（310 H不锈钢）在550°C的超临界温度和250 atm的压力下长达2160 h的水中的腐蚀行为。在超临界温度下，水是一种高度侵蚀性的环境，用于超临界水冷核反应堆（SCWR）的结构材料的腐蚀是一个关键问题。选择合适的候选材料是SCWR开发的关键问题之一。暴露于脱气的超临界水中后，使用重量分析，金相分析和电化学方法对310 H SS表面上形成的氧化物进行表征。重量分析表明，由于氧化，所有测试样品均变重，并且550°C下310H不锈钢的氧化遵循抛物线速率，表明它是由扩散过程驱动的。通过显微金相学获得的数据与通过重量分析获得的数据一致，并且表明氧化物层随时间具有增长的趋势。同时，通过电化学阻抗谱（EIS）测量获得的结果表明Cr和（Fe，Mn）Cr的最佳耐腐蚀性氧化2160小时后，在样品表面形成₂ O ₄氧化物。根据获得的结果，发现重量分析，金相分析和电化学方法之间具有很强的相关性。