Dense, uniform, and well-adhered chromium (Cr) coatings were deposited on zirconium (Zr) alloy claddings by using physical vapor deposition (PVD). The Cr-coated samples were tested at 1200 ^oC and 1300 ^oC, respectively, for different exposure time in water steam environment. Microstructures and compositions of the coating/substrate system after oxidation were characterized by X-ray diffraction, scanning electronic microscopy, and energy dispersion spectrometer. The microstructural results clearly demonstrated that Cr₂O₃ layer has been produced on the coating surface, acting as an oxygen diffusion barrier and concomitantly reducing the oxidation rate. The experimental results on weight gains soundly supported the microstructural findings that the Cr coatings could protect the Zr substrate from high-temperature steam oxidation, even at a temperature up to 1300 ^oC. Finally, the oxidation kinetics was theoretically analyzed and the underlying oxidation mechanism was also clarified.

使用物理气相沉积（PVD）将致密，均匀且粘附良好的铬（Cr）涂层沉积在锆（Zr）合金熔覆层上。在水蒸汽环境中，分别在1200 ^o C和1300  ^o C下测试Cr涂层样品的 暴露时间。通过X射线衍射，扫描电子显微镜和能谱仪表征了氧化后的涂层/基体系统的微观结构和组成。显微组织结果清楚地表明Cr ₂ O ₃在涂层表面上已形成一层氧化层，作为氧气的扩散阻挡层，并随之降低了氧化速率。关于增重的实验结果有力地证明了微观结构的发现，即即使在高达1300 ^o C的温度下，Cr涂层也能保护Zr衬底免受高温蒸汽氧化 。最后，从理论上分析了氧化动力学并分析了其潜在的氧化机理也得到了澄清。