Effect of surface finishing on the oxidation characteristics of a Fe-21Cr-32Ni alloy in supercritical carbon dioxide
Effect of surface finishing on the oxidation characteristics of a Fe-21Cr-32Ni alloy in supercritical carbon dioxide
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DOI：
10.1016/j.corsci.2021.110019
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发表时间：
2022-02-01
影响因子：
8.3
通讯作者：
Zeng, Xiaoqin
中科院分区：
文献类型：
--
作者：
Chen, Kai;Liu, Zhu;Zeng, Xiaoqin
研究了表面处理对Fe-21Cr-32Ni合金在超临界二氧化碳（650℃，1000 h）中氧化行为的影响。暴露后，试样的横截面呈现出典型的内外氧化层结构，并伴有亚表面渗碳。在地面上发现了较低的氧化和渗碳速率，其中观察到更薄的富cr氧化层和较浅的渗碳深度。磨削在金属表面形成超细晶层和高度变形层，Cr的扩散速率显著提高。高Cr的扩散有利于形成薄的/保护性的富Cr氧化层，从而导致从内部氧化到外部氧化的转变。这种连续的富cr氧化层不仅可以防止基体进一步氧化，还可以降低碳对氧化物的渗透性，从而提高接地试样的抗氧化和抗渗碳能力。
The effect of surface finishing on the oxidation behavior of a Fe-21Cr-32Ni alloy in supercritical carbon dioxide (650 degrees C for 1000 h) was studied. After exposure, the cross-section of the specimen showed a typical inner-outer oxide layers structure with subsurface carburization. Reduced oxidation and carburization rates were identified for the ground surface, where a much thinner Cr-rich oxide scale and a shallower carburization depth were observed. Grinding introduced an ultra-fine grained layer and a highly deformed layer on the metal surface, where Cr diffusion rate was significantly enhanced. The high Cr diffusion led to the transition from internal to external oxidation by favoring the formation of a thin/protective Cr-rich oxide layer. This continuous Cr-rich oxide layer not only protected the substrate matrix from further oxidation, but also reduced the permeability of carbon into the oxides, thus improving the oxidation and carburization resistance of the ground specimen.