from the conferences organized by TANGER Ltd.
The corrosion coupons of 800H alloy with TIG weld filled with Nicrofer were exposed to impure helium in the High-Temperature Furnace (HTF) at 760 °C for 372, 1000 and 1500 hours. Impurities CH4, CO, H2 and H2O were chosen to simulate conditions in a High-Temperature Gas Reactor system (HTGR). The specimen surface, corrosion layer thickness and composition were evaluated by Scanning Electron Microscope (SEM) with Energy Dispersive Spectroscopy (EDS). Specimens were covered with a uniform protective oxide layer up to 3 µm thick, growing with exposure time. The layer contained mainly Cr, O2 and a minor amount of Mn. Localized deep oxidation was found after 1500 hours in between the weld and base material. The output of these measurements is the evaluation of the properties of the tested materials and the assessment of their resistance to corrosion effects. 800H alloy and Nicrofer alloy were found to degrade similarly in an oxidizing environment. This combination of base material and weld metal appears to be suitable for use at high temperatures.
Keywords: Nuclear application, helium, corrosion layer, alloy 800H, alloy Nicrofer© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.