The corrosion resistance of structural materials has been recognized as a key issue in the various unit operations such as salt purification, electrorefining, cathode processing and injection casting in the pyrochemical reprocessing of spent metallic nuclear fuels. In the present work, the corrosion behavior of the candidate materials of stainless steel (SS) 410, 2.25Cr-1Mo and 9Cr-1Mo steels was investigated in molten LiCl-KCl-UCl₃ salt by thermogravimetric analysis under inert and reactive atmospheres at 500 and 600 °C, for 6 h duration. Insignificant weight gain (less than 1 mg/cm²) in the inert atmosphere and marginal weight gain (maximum 5 mg/cm²) in the reactive atmosphere were observed at both the temperatures. Chromium depletion rates and formation of Cr-rich corrosion products increased with increasing temperature of exposure in both inert and reactive atmospheres as evidenced by SEM and EDS analysis. The corrosion attack by LiCl-KCl-UCl₃ molten salt, under reactive atmosphere for 6 h duration was more in the case of SS410 than 9Cr-1Mo steel followed by 2.25Cr-1Mo steel at 500 °C and the corrosion attack at 600 °C followed the order: 9Cr-1Mo steel >2.25Cr-1Mo steel > SS410. Outward diffusion of the minor alloying element, Mo was observed in 9Cr-1Mo and 2.25Cr-1Mo steels at both temperatures under reactive atmosphere. Laser Raman spectral analysis of the molten salt corrosion tested alloys under a reactive atmosphere at 500 and 600 °C for 6 h revealed the formation of unprotected Fe₃O₄ and α-as well as γ-Fe₂O₃. The results of the present study facilitate the selection of structural materials for applications in the corrosive molten salt environment at high temperatures.

结构材料的耐腐蚀性已被认为是各种单元操作中的关键问题，例如盐纯化，电精炼，阴极处理和乏金属核燃料热化学后处理中的注模铸造。在目前的工作中，通过在惰性和反应性气氛下于500℃下进行热重分析，研究了在熔融的LiCl-KCl-UCl ₃盐中，不锈钢（SS）410、2.25Cr-1Mo和9Cr-1Mo候选材料的腐蚀行为。600°C，持续6小时。在惰性气氛中微不足道的重量增加（小于1 mg / cm ²）和边际重量增加（最大5 mg / cm ^2）在两个温度下均在反应性气氛中观察到）。SEM和EDS分析表明，在惰性和反应性气氛中，随着暴露温度的升高，铬的贫化速率和富铬腐蚀产物的形成也随之增加。LiCl-KCl-UCl ₃的腐蚀作用在SS410的情况下，在反应性气氛下持续6 h的熔融盐持续时间要比9Cr-1Mo钢高，其次是在500°C时为2.25Cr-1Mo钢，在600°C时的腐蚀速率遵循以下顺序：9Cr-1Mo钢> 2.25Cr-1Mo钢> SS410。在两种温度和反应气氛下，在9Cr-1Mo和2.25Cr-1Mo钢中均观察到微量合金元素的向外扩散。熔融盐腐蚀的激光拉曼光谱分析在500反应性气氛下进行试验的合金和600℃下6小时的显示未受保护形成的Fe ₃ ö ₄和α-以及γ-的Fe ₂ ö ₃。本研究的结果促进了在高温熔融盐环境中应用的结构材料的选择。