Bright O. Okonkwo , Chaewon Kim , Taejeong An , Changheui Jang , Dokyu Kang , Wonseok Yang , Sungyeol Choi
{"title":"含铝合金在 Cl 基熔盐环境中的腐蚀行为","authors":"Bright O. Okonkwo , Chaewon Kim , Taejeong An , Changheui Jang , Dokyu Kang , Wonseok Yang , Sungyeol Choi","doi":"10.1016/j.jnucmat.2024.155207","DOIUrl":null,"url":null,"abstract":"<div><p>The corrosion behaviour of Al-containing alloys in KCl-MgCl<sub>2</sub> at 700 °C was investigated and compared with that of commercial alloys. The developed Al-containing alloys showed less or similar weight loss compared to Hastelloy N owing to Al-rich oxide formation. While 316 SS showed both uniform and localised corrosion, a high Al-containing alloy was almost unattacked by any form of corrosion. The SEM map in this study innovatively showed and confirmed the high Cr depletion at the top matrix layer of the exposed 316 SS alloy. It was found that the primary controlling mechanism of corrosion is the outward diffusion of metal ions promoted by the volatile metal chlorides, while Cr diffusion was detrimental, Al diffusion was beneficial in mitigating corrosion via the formation of Al oxides. Noteworthily, this study revealed that the KCl-MgCl<sub>2</sub> salt was very corrosive to the 316 SS, and its interaction led to an obvious intergranular corrosion arising from Cr-depletion of the grain boundaries due to the high Cr content of the 316 SS. While for the high Al-containing alloys, the ACES with lower Al content and higher Ni content exhibited a higher corrosion rate when in contact with KCl-MgCl<sub>2</sub>salt than the ADSS with higher Al content and lower Ni content. The mechanism of electrochemical interaction between the KCl-MgCl<sub>2</sub> salt and the high Al-containing alloys was that, the increased Al content and decreased Ni content enabled the formation of α – Al<sub>2</sub>O<sub>3</sub>, which provided excellent protective barrier against corrosion attack, while, the lower Al and higher Ni contents lead to the formation of Mg and Ni aluminate oxides. These oxides were less protective against corrosion attack in the molten salt environment.</p></div>","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":null,"pages":null},"PeriodicalIF":2.8000,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Corrosion behaviour of Al-containing alloys in Cl-based molten salt environment\",\"authors\":\"Bright O. Okonkwo , Chaewon Kim , Taejeong An , Changheui Jang , Dokyu Kang , Wonseok Yang , Sungyeol Choi\",\"doi\":\"10.1016/j.jnucmat.2024.155207\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>The corrosion behaviour of Al-containing alloys in KCl-MgCl<sub>2</sub> at 700 °C was investigated and compared with that of commercial alloys. The developed Al-containing alloys showed less or similar weight loss compared to Hastelloy N owing to Al-rich oxide formation. While 316 SS showed both uniform and localised corrosion, a high Al-containing alloy was almost unattacked by any form of corrosion. The SEM map in this study innovatively showed and confirmed the high Cr depletion at the top matrix layer of the exposed 316 SS alloy. It was found that the primary controlling mechanism of corrosion is the outward diffusion of metal ions promoted by the volatile metal chlorides, while Cr diffusion was detrimental, Al diffusion was beneficial in mitigating corrosion via the formation of Al oxides. Noteworthily, this study revealed that the KCl-MgCl<sub>2</sub> salt was very corrosive to the 316 SS, and its interaction led to an obvious intergranular corrosion arising from Cr-depletion of the grain boundaries due to the high Cr content of the 316 SS. While for the high Al-containing alloys, the ACES with lower Al content and higher Ni content exhibited a higher corrosion rate when in contact with KCl-MgCl<sub>2</sub>salt than the ADSS with higher Al content and lower Ni content. The mechanism of electrochemical interaction between the KCl-MgCl<sub>2</sub> salt and the high Al-containing alloys was that, the increased Al content and decreased Ni content enabled the formation of α – Al<sub>2</sub>O<sub>3</sub>, which provided excellent protective barrier against corrosion attack, while, the lower Al and higher Ni contents lead to the formation of Mg and Ni aluminate oxides. These oxides were less protective against corrosion attack in the molten salt environment.</p></div>\",\"PeriodicalId\":373,\"journal\":{\"name\":\"Journal of Nuclear Materials\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.8000,\"publicationDate\":\"2024-06-04\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Nuclear Materials\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S002231152400309X\",\"RegionNum\":2,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"MATERIALS SCIENCE, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Nuclear Materials","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S002231152400309X","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
摘要
研究了含铝合金在 700 °C 的 KCl-MgCl2 中的腐蚀行为,并与商用合金的腐蚀行为进行了比较。与哈氏合金 N 相比,由于富铝氧化物的形成,所开发的含铝合金的重量损失较小或相似。316 SS 出现了均匀腐蚀和局部腐蚀,而高含铝量合金几乎没有受到任何形式的腐蚀。本研究中的扫描电子显微镜图创新性地显示并证实了暴露在外的 316 SS 合金基体顶层的高铬损耗。研究发现,腐蚀的主要控制机制是金属离子在挥发性金属氯化物的促进下向外扩散,而铬的扩散是有害的,铝的扩散则有利于通过形成铝氧化物来减轻腐蚀。值得注意的是,这项研究发现 KCl-MgCl2 盐对 316 SS 有很强的腐蚀性,由于 316 SS 的铬含量较高,其相互作用导致晶界铬耗竭而产生明显的晶间腐蚀。而对于含铝量高的合金,与含铝量高和含镍量低的 ADSS 相比,含铝量低和含镍量高的 ACES 在与 KCl-MgCl2 盐接触时表现出更高的腐蚀速率。KCl-MgCl2 盐与高铝合金之间的电化学作用机理是,铝含量增加和镍含量降低可形成 α - Al2O3,为腐蚀提供良好的保护屏障,而铝含量较低和镍含量较高则会形成镁和镍铝酸盐氧化物。这些氧化物在熔盐环境中对腐蚀侵蚀的保护作用较弱。
Corrosion behaviour of Al-containing alloys in Cl-based molten salt environment
The corrosion behaviour of Al-containing alloys in KCl-MgCl2 at 700 °C was investigated and compared with that of commercial alloys. The developed Al-containing alloys showed less or similar weight loss compared to Hastelloy N owing to Al-rich oxide formation. While 316 SS showed both uniform and localised corrosion, a high Al-containing alloy was almost unattacked by any form of corrosion. The SEM map in this study innovatively showed and confirmed the high Cr depletion at the top matrix layer of the exposed 316 SS alloy. It was found that the primary controlling mechanism of corrosion is the outward diffusion of metal ions promoted by the volatile metal chlorides, while Cr diffusion was detrimental, Al diffusion was beneficial in mitigating corrosion via the formation of Al oxides. Noteworthily, this study revealed that the KCl-MgCl2 salt was very corrosive to the 316 SS, and its interaction led to an obvious intergranular corrosion arising from Cr-depletion of the grain boundaries due to the high Cr content of the 316 SS. While for the high Al-containing alloys, the ACES with lower Al content and higher Ni content exhibited a higher corrosion rate when in contact with KCl-MgCl2salt than the ADSS with higher Al content and lower Ni content. The mechanism of electrochemical interaction between the KCl-MgCl2 salt and the high Al-containing alloys was that, the increased Al content and decreased Ni content enabled the formation of α – Al2O3, which provided excellent protective barrier against corrosion attack, while, the lower Al and higher Ni contents lead to the formation of Mg and Ni aluminate oxides. These oxides were less protective against corrosion attack in the molten salt environment.
期刊介绍:
The Journal of Nuclear Materials publishes high quality papers in materials research for nuclear applications, primarily fission reactors, fusion reactors, and similar environments including radiation areas of charged particle accelerators. Both original research and critical review papers covering experimental, theoretical, and computational aspects of either fundamental or applied nature are welcome.
The breadth of the field is such that a wide range of processes and properties in the field of materials science and engineering is of interest to the readership, spanning atom-scale processes, microstructures, thermodynamics, mechanical properties, physical properties, and corrosion, for example.
Topics covered by JNM
Fission reactor materials, including fuels, cladding, core structures, pressure vessels, coolant interactions with materials, moderator and control components, fission product behavior.
Materials aspects of the entire fuel cycle.
Materials aspects of the actinides and their compounds.
Performance of nuclear waste materials; materials aspects of the immobilization of wastes.
Fusion reactor materials, including first walls, blankets, insulators and magnets.
Neutron and charged particle radiation effects in materials, including defects, transmutations, microstructures, phase changes and macroscopic properties.
Interaction of plasmas, ion beams, electron beams and electromagnetic radiation with materials relevant to nuclear systems.