Characteristics of hybrid tube with Fe-high Si alloy lining by centrifugal casting for thermochemical water-splitting iodine-sulfur process

Ioka, Ikuo  ; Kuriki, Yoshiro*; Iwatsuki, Jin ; Kubo, Shinji  ; Katsuyama, Jinya  ; Inagaki, Yoshiyuki

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.