Abstract
The under-deposit corrosion behavior of Ni-based alloys 625, 825 and Fe-based alloy 800 in supercritical water (SCW) at 400 °C and 500 °C was investigated. Newly designed experimental apparatus was used to ensure that the surface of alloy specimens was covered by NaCl or KCl deposit layers during the corrosion test in SCW environment. Based on the cross-sectional observation and surface chemical analyses, the oxide film on the samples after exposure contains an outer layer containing Fe-Ni-Cr spinel and Fe3O4, and an inner layer of Cr2O3. NiCl2 was also found on the alloy surface. At 400 °C, hydrolysis of the metallic ions occurred, forming HCl with chloride ions. At 500 °C, the oxides react with the solid-phase salt deposit via the formation and transformation of the HCl vapor. The salt deposit layer acted as a barrier for the diffusion of SCW and HCl vapor at 500 °C.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
