This study considers the different engineering application environments for normal use and emergency repair of reinforced concrete structures. The natural passivation and chloride corrosion resistance of Inconel 625 in Ordinary Portland cement (OPC) and Calcium Sulfoaluminate cement (CSA) was first evaluated through electrochemical measurement and surface analysis techniques. OPC and CSA related to different pH values of pore solutions were selected while low carbon (LC) steel and 304 stainless steels (304SS) were also investigated as reference. The electrochemical test results showed that the passivation ability of 304SS and Inconel 625 in CSA solution was as well as or better than that in OPC solution, while LC steel could hardly be passivated in CSA solution. In addition, X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) results indicated that the thickness and integrity of the Inconel 625 passivation film were lower than that of 304SS. Notably, the thicknesses of Inconel 625 and 304SS in CSA solution are 4.6 nm and 5.2 nm, respectively. However, the corrosion resistance of Inconel 625 in chloride environments was significantly better than that of 304SS, which was attributed to the presence of highly corrosion-resistant Cr, Ni, and Mo compounds on the surface of Inconel 625 passivation film. Finally, based on the research results, the passivation and chloride corrosion resistance mechanism of Inconel 625 in OPC and CSA solutions was proposed, which may provide a reference and theoretical basis for the application of Inconel 625 in cement-based materials. In particular, the introduction of Inconel 625 is of great significance in improving the durability of concrete structures for emergency construction projects using CSA in complex and harsh environments.

中文翻译：

---

Inconel 625 在不同 pH 值的 OPC 和 CSA 混凝土孔隙溶液中的自然钝化和耐氯化物腐蚀性能


本研究考虑了钢筋混凝土结构正常使用和紧急修复的不同工程应用环境。首先通过电化学测量和表面分析技术评估了 Inconel 625 在普通硅酸盐水泥 （OPC） 和磺基铝酸钙水泥 （CSA） 中的自然钝化和耐氯化物腐蚀性能。选择了与孔隙溶液不同 pH 值相关的 OPC 和 CSA，同时还研究了低碳 （LC） 钢和 304 不锈钢 （304SS） 作为参考。电化学测试结果表明，304SS 和 Inconel 625 在 CSA 溶液中的钝化能力与 OPC 溶液相当或更好，而液相色谱钢在 CSA 溶液中几乎不能钝化。此外，X 射线光电子能谱 （XPS） 和原子力显微镜 （AFM） 结果表明，Inconel 625 钝化膜的厚度和完整性低于 304SS。值得注意的是，Inconel 625 和 304SS 在 CSA 溶液中的厚度分别为 4.6 nm 和 5.2 nm。然而，Inconel 625 在氯化物环境中的耐腐蚀性明显优于 304SS，这归因于 Inconel 625 钝化膜表面存在高度耐腐蚀的 Cr、Ni 和 Mo 化合物。最后，基于研究结果，提出了 Inconel 625 在 OPC 和 CSA 溶液中的钝化和抗氯化物腐蚀机理，可为 Inconel 625 在水泥基材料中的应用提供参考和理论依据。 特别是，Inconel 625 的推出对于提高在复杂和恶劣环境中使用 CSA 的紧急建筑项目的混凝土结构的耐久性具有重要意义。