Background: The invalidation problems of irradiated Hastelloy N alloy caused by high temperature

intense irradiation and severe corrosion are the key factors to the service life of structural materials of molten salt reactor (MSR). Purpose: The aim is to investigate the effect of absorbed dose on the corrosion resistance of Hastelloy N alloy. Methods: Hastelloy N alloy was irradiated by 4.5-MeV He+ ions

and the absorbed doses were 0 He+?cm?2

1×1015 He+?cm?2

5×1015 He+?cm?2 and 1×1016 He+?cm?2 respectively. The virgin and irradiated specimens were immersed into molten fluoride salts at 700 oC for 300 h. Then the corroded specimens were imaged by scanning electron microscopy and analyzed by synchrotron radiation microbeam X-ray fluorescence (?-XRF). Results: The weight-loss results showed that the corrosion generally correlated with the absorbed dose of the alloy. The ?-XRF results indicated that the corrosion was mainly due to the dealloying of alloying element Cr in the matrix. Conclusion: The density of dislocations of Hastelloy N alloy increased with the absorbed dose

which acted as quick paths for Cr element diffusion

and the diffusion of element Cr out of matrix became easier. Finally became weak of the corrosion resistance of Hatelloy N alloy.Cited