The isothermal steam oxidation experiments of Cr-coated Zr alloy cladding at 1350 ℃ were conducted, and the influence of Cr-Zr eutectic reaction on the oxidation behavior was investigated. The oxidation duration, ranging from 50 s to 3600 s, covers the cases from the initial formation of eutectic liquid to the complete oxidation of the cladding. The microstructures of the coating and the substrate were characterized. The eutectic-oxidation degradation mechanism of the coating is summarized. The migration of the eutectic liquid and the evolution of Cr-rich phases in the post-oxidation eutectic structure are studied and discussed, confirming the process of ZrCr reacting with α-Zr(O) to form ZrCrO. The degraded Cr coating and the Cr retained in ZrO during the migration of the eutectic liquid can hardly affect the oxidation of cladding substrate. However, the Cr-rich phases, which eventually aggregated in the radial center of the cladding, can reduce the oxidation rate.

中文翻译：

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1350 ℃蒸汽中Cr涂层Zr合金熔壳共晶和氧化反应的等温实验：行为、机理和动力学

对Cr包覆Zr合金熔壳进行1350 ℃等温蒸汽氧化实验，研究Cr-Zr共晶反应对氧化行为的影响。氧化持续时间范围为50 s至3600 s，涵盖了从共晶液体最初形成到熔壳完全氧化的情况。对涂层和基体的微观结构进行了表征。总结了涂层的共晶氧化降解机理。对共晶液的迁移和氧化后共晶组织中富Cr相的演化进行了研究和讨论，证实了ZrCr与α-Zr(O)反应生成ZrCrO的过程。降解的Cr涂层和共晶液迁移过程中残留在ZrO中的Cr几乎不影响熔覆基体的氧化。然而，富铬相最终聚集在包壳的径向中心，可以降低氧化速率。