The harsh work environments caused by high-temperature, high-pressure water, especially the presence of aggressive species such as oxygen and salts, makes equipment corrosion to be a key problem restricting large-scale industrial application of the supercritical water technologies. In this work, the corrosion characteristics of Ni-Fe-Cr and Ni-Fe-Cr-Mo-Cu corrosion-resistant alloys, such as the corrosion rate, the structure and composition of oxide film, and the effects of various surface treatment processes, are discussed in detail. The corrosion mechanisms of typical Ni-based alloys in supercritical water are analyzed. Inconel 625 and Hastelloy C-276 possess good corrosion resistance over a wide range of test environments, in terms of current investigation data regarding Ni-based alloys. The outer layer is formed by a metal passive dissolution-oxide precipitation mechanism, and the precipitated metal ions are released from the barrier layer. The looseness and discontinuity of the outer oxide layer can be attributed to the decomposition of oxides in the layer, the scouring of external fluids, or growth via electro-crystallization. This information is valuable for theoretically guiding material selection and design and operating parameter optimization of key equipment in the supercritical water technologies.

由高温高压水引起的恶劣工作环境，特别是氧气和盐等侵蚀性物质的存在，使设备腐蚀成为限制超临界水技术大规模工业应用的关键问题。在这项工作中，Ni-Fe-Cr和Ni-Fe-Cr-Mo-Cu耐腐蚀合金的腐蚀特性，例如腐蚀速率，氧化膜的结构和组成，以及各种表面处理工艺的影响，将详细讨论。分析了典型的镍基合金在超临界水中的腐蚀机理。根据有关镍基合金的最新研究数据，Inconel 625和Hastelloy C-276在广泛的测试环境中均具有良好的耐腐蚀性。外层通过金属钝化溶解氧化物沉淀机理形成，并且沉淀的金属离子从阻挡层释放。外部氧化物层的疏松和不连续性可归因于该层中氧化物的分解，外部流体的冲刷或通过电结晶的生长。这些信息对于从理论上指导超临界水技术中关键设备的材料选择，设计和运行参数优化具有重要价值。