了解导致合金在高温下在熔盐中降解的机理对于开发几种关键的能源产生和存储技术具有重要意义。包括集中太阳能和下一代核电站。具体来说,不同类型的腐蚀导致各种形态演变特征的基本机制,改变熔盐和合金之间的反应条件仍不清楚。在这项工作中,通过结合原位同步加速器X射线和电子显微镜技术,在600°C下研究了KCl-MgCl2中Ni-20Cr的三维(3D)形态演变。通过进一步比较500-800°C温度范围内的不同形态演变特征,盐-金属界面处的扩散和反应之间的相对速率导致不同的形态演化途径,包括晶间腐蚀和渗滤脱合金。在这项工作中,讨论了金属与熔盐之间相互作用的温度依赖性机理,为预测实际应用中的熔盐腐蚀提供见解。
Understanding the mechanisms leading to the degradation of alloys in molten salts at elevated temperatures is significant for developing several key energy generation and storage technologies, including concentrated solar and next-generation nuclear power plants. Specifically, the fundamental mechanisms of different types of corrosion leading to various morphological evolution characteristics for changing reaction conditions between the molten salt and alloy remain unclear. In this work, the three-dimensional (3D) morphological evolution of Ni-20Cr in KCl-MgCl2 is studied at 600 °C by combining in situ synchrotron X-ray and electron microscopy techniques. By further comparing different morphology evolution characteristics in the temperature range of 500-800 °C, the relative rates between diffusion and reaction at the salt-metal interface lead to different morphological evolution pathways, including intergranular corrosion and percolation dealloying. In this work, the temperature-dependent mechanisms of the interactions between metals and molten salts are discussed, providing insights for predicting molten salt corrosion in real-world applications.