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Ioka, Ikuo; Kuriki, Yoshiro*; Iwatsuki, Jin; Kawai, Daisuke*; Yokota, Hiroki*; Inagaki, Yoshiyuki; Kubo, Shinji
Proceedings of 2020 International Conference on Nuclear Engineering (ICONE 2020) (Internet), 5 Pages, 2020/08
A thermochemical water-splitting iodine-sulfur processes (IS process) is one of candidates for the large-scale production of hydrogen using heat from solar power. Severe corrosive environment which is thermal decomposition of sulfuric acid exists in the IS process. A hybrid material with the corrosion-resistance and the ductility was made by a plasma spraying and laser treatment. The specimen had excellent corrosion resistance in the condition of 95 mass% boiling sulfuric acid. This was attributed to the formation of SiO
on the surface. The container using the hybrid material was experimentally made. The pre-oxidized container using hybrid technique was prepared for the corrosion test in boiling sulfuric acid to evaluate the corrosion characteristics of the container. There was no detaching of the surface with the weld part and the R processing. We proposed the calculation method of corrosion rate from the ions dissolved in the sulfuric acid solution after the corrosion test.
Ioka, Ikuo; Kuriki, Yoshiro*; Iwatsuki, Jin; Kubo, Shinji; Katsuyama, Jinya; Inagaki, Yoshiyuki
Mechanical Engineering Journal (Internet), 3(3), p.15-00619_1 - 15-00619_8, 2016/06
The IS process for hydrogen production has been developed by JAEA as application of a high-temperature gas cooled reactor. The IS process includes a severe corrosion environment which is made to boil and decompose concentrated sulfuric acid. The two-layer pipe consisted of the Fe-high Si alloy with boiling sulfuric acid-resistant and the carbon steel with the ductility was produced by centrifugal casting. The evaluation of characteristics was carried out. The Fe-high Si alloy lining showed enough corrosion resistance in boiling sulfuric acid. As evaluation of the Fe / Fe-high Si alloy interface, thermal cycle test was executed. There was no detachment of the interface though the cracks were generated in the vicinity of the interface. It is believed that the cracks parallel to the interface is attributed to the tensile stress during the thermal cyclic test using FEM analysis and the flake graphite precipitate. It was confirmed that the interface possessed the enough strength.
Ioka, Ikuo; Kuriki, Yoshiro*; Iwatsuki, Jin; Kubo, Shinji; Inagaki, Yoshiyuki
Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM), 6 Pages, 2015/05
The thermochemical water-splitting (IS process) for hydrogen production has been developed by JAEA as application of a high-temperature gas cooled reactor. The IS process includes a severe corrosion environment which is made to boil and decompose concentrated sulfuric acid. Two kinds of brittleness materials, SiC and Fe-high Si alloy, are reported as materials having enough corrosion resistance in this corrosion environment. The two-layer pipe consisted of the Fe-high Si alloy with boiling sulfuric acid-resistant and the carbon steel with the ductility was produced by centrifugal casting. The evaluation of characteristics was carried out. The Fe-high Si alloy lining showed enough corrosion resistance in boiling sulfuric acid. As evaluation of the Fe / Fe-high Si alloy interface, thermal cycle test (100
C-900C) was executed. There was not the interface detachment and it was confirmed to have enough interfacial strength.
Ioka, Ikuo; Kuriki, Yoshiro*; Iwatsuki, Jin; Kubo, Shinji; Inagaki, Yoshiyuki; Sakaba, Nariaki
no journal, ,
Hydrogen is one of the promising major energy sources in the future. IS process is one of candidates for the large-scale production of hydrogen using heat from solar power. Severe corrosive environment which is thermal decomposition of sulfuric acid exists in the IS process. To achieve a massive hydrogen production system, one of the key factors is the development of structural materials. A hybrid material that combined the corrosion-resistant and the pressure-resistant functions was made by a plasma spraying and laser treatment. The flat specimen of the hybrid material showed enough corrosion resistance in boiling sulfuric acid. To confirm the applicability of the hybrid material as the structural material, corrosion tests were performed in 98 wt.% boiling sulfuric acid using round bar specimens with the curved surface. The specimens showed enough corrosion resistance in boiling sulfuric acid though some cracks were observed in the surface layer from the cross section observation.
Ioka, Ikuo; Kuriki, Yoshiro*; Iwatsuki, Jin; Kubo, Shinji; Inagaki, Yoshiyuki; Sakaba, Nariaki
no journal, ,
IS process is one of candidates for the large-scale production of hydrogen. Thermal decomposition of sulfuric acid exists in the IS process. A hybrid material with the corrosion-resistance and the ductility was made by a plasma spraying and laser treatment. The specimen had excellent corrosion resistance in the condition of 95 mass% boiling sulfuric acid. The corrosion rate of the specimen in 47 mass% boiling sulfuric acid was fifty times higher than that in 95 mass% boiling sulfuric acid. It seems that the cracks of the surface layer weren't sealed up perfectly in the condition of 47 mass% boiling sulfuric acid. To improve the corrosion resistance of the specimen, the specimen was treated with a thermal treatment for pre-oxidation. The pre-oxidized specimen got superior corrosion resistance in the condition of 47 mass% boiling sulfuric acid. It was confirmed that the pre-oxidation was effective in improving corrosion resistance of the specimen.
