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    310S和316L不锈钢在超临界二氧化碳环境中的均匀腐蚀行为

    General Corrosion Behavior of 310S and 316L Stainless Steels in Supercritical Carbon Dioxide

    • 摘要: 在600 ℃、20 MPa超临界二氧化碳(S-CO2)环境中研究了310S和316L奥氏体不锈钢的腐蚀行为。在静态高压釜中对两种不锈钢进行了500 h的均匀腐蚀试验,采用扫描电子显微镜(SEM)、能谱仪(EDS)、X射线衍射仪(XRD)等观察和分析了试样表面氧化膜的形貌、成分及结构。结果表明:310S不锈钢的耐蚀性优于316L不锈钢,腐蚀500 h后两种不锈钢的质量增量分别为6.82 mg/dm2和35.25 mg/dm2;310S不锈钢表面氧化膜厚约1 μm,外层为Fe-Cr-Ni尖晶石,内层为Cr2O3,结构致密具有保护性;316L不锈钢表面氧化膜厚约5 μm,外层为Fe3O4,内层为Fe-Cr-Ni尖晶石,结构疏松不具有保护性。造成两种不锈钢腐蚀行为差异的原因是其铬含量不同。

       

      Abstract: The corrosion behavior of 310S and 316L austenite stainless steels in the supercritical carbon dioxide (S-CO2) environment of 600 ℃/20 MPa was investigated. The general corrosion tests were carried out in an aoutoclave for 500 h. The morphology, composition and structure of the oxide films on sample surfaces were characterized by scanning electron micro-scopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The results show that the corrosion resistance of 310S stainless steel was higher than that of 316L stainless steel, and the weight gains of stainless steels 310S and 316L corroded for 500 h were 6.82 mg/dm2 and 35.25 mg/dm2, respectively. The thickness of oxide scale on 310S was about 1 μm, with an outer Fe-Cr-Ni spinel layer and an inner Cr2O3 layer which was dense and continuous. The thickness of oxide scale on 316L was about 5 μm with an outer Fe3O4 layer and an inner Fe-Cr-Ni spinel layer which was loose and not protective. The the difference in the corrosion behavior between 310S and 316L was due to their different Cr concentrations.

       

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