超超临界机组HR3C不锈钢蒸汽侧氧化层的微观结构和生长机理

Microstructure and Growth Mechanism of the Oxide Scale Formed on HR3C at the Steam Side in Ultra Supercritical(USC) Units

对华能玉环电厂运行了5400h和23400h的HR3C末级再热器管取样,对蒸汽侧氧化层的结构、形貌和微区元素分布规律进行了研究。结果发现,随着氧化的深入,HR3C蒸汽侧氧化层由二层结构发展成为四层结构,靠近氧化层的基体金属中的贫Cr是氧化层生长的捷径。探讨了HR3C蒸汽侧氧化层的生长机理。

The structure, morphology and elemental micro-distributions of the steam side oxide scale of the HR3C reheater tubes after operation for 5400 h and 23400 h, respectively, in Huaneng Yuhuan Power Plant were studied. It was found that with the advance of oxidation process, the steam side oxide scale of HR3C tubes developed from a double-layer structure to a four-layer structure and the Cr-depleted zone was the shortcut for the growth of the oxide scale. The growth mechanism of the steam side oxide scale on HR3C was also discussed.