Centro de Investigación en Ingeniería y Ciencias Aplicadas, Universidad Autónoma del Estado de Morelos, Avenida Universidad 1001, Cuernavaca 62209, Mexico.
Tecnológico Nacional de Mexico-Instituto Tecnológico de Zacatepec, Calzada Instituto Tecnológico 27, Zacatepec 62780, Mexico.
Int J Mol Sci. 2022 Jul 18;23(14):7895. doi: 10.3390/ijms23147895.
This study reports the behavior of the Ni20Cr alloy in molten nitrate salts. Its behavior was evaluated in the eutectic mixture called Solar Salt (binary salt) and in a ternary mixture (90% Solar Salt and 10% lanthanum nitrate). The addition of lanthanum nitrate was performed to determine if the presence of the La cation could act as a corrosion inhibitor. Through mass loss and potentiodynamic polarization studies, the effects of both electrolytes on the corrosion resistance of the alloy at 300, 400, and 500 °C and at exposure times of 250, 500, 750, and 1000 h were determined. The results showed an increase in the corrosivity of the ternary salt, due to a decrease in its melting point and an increase in the concentration of nitrate ions. However, it was observed that the La cations formed a protective layer (LaO) on the alloy surface. In both corrosive media, the Ni20Cr alloy showed excellent corrosion resistance, due to its ability to form protective layers of CrO, NiO, and NiCrO, in addition to the presence of a layer of LaO in the case of the ternary salt.
本研究报告了 Ni20Cr 合金在熔融硝酸盐中的行为。评估了其在称为 Solar Salt（二元盐）和三元混合物（90% Solar Salt 和 10%硝酸镧）中的行为。添加硝酸镧是为了确定镧阳离子的存在是否可以作为腐蚀抑制剂。通过质量损失和动电位极化研究，确定了两种电解质在 300、400 和 500°C 以及暴露时间为 250、500、750 和 1000 h 下对合金耐腐蚀性的影响。结果表明，由于三元盐的熔点降低和硝酸根离子浓度增加，其腐蚀性增加。然而，观察到镧阳离子在合金表面形成了一层保护层（LaO）。在这两种腐蚀性介质中，Ni20Cr 合金表现出优异的耐腐蚀性，因为它能够形成 CrO、NiO 和 NiCrO 的保护层，而在三元盐的情况下还存在一层 LaO。
