Effect of irradiation damage defects on the impurity containing molten salt corrosion behavior in GH3535 alloy

• Published in: Corrosion science 2023-10, Vol.223, p.111475, Article 111475
• Main Authors: Ji, Weichi, Zhu, Zhenbo, Huang, Hefei, Leng, Bin, Lei, Guanhong, Li, Yan
• Format: Article
• Language: English
• Subjects: Displacement damage; He bubbles; Impurity; Molten salt corrosion; Nickel based alloy
• ISSN: 0010-938X
• DOI: 10.1016/j.corsci.2023.111475

This study explores the corrosion response of irradiated nickel-based GH3535 alloy in impurity-enriched molten FLiNaK salt at 650 °C. Displacement damage resulting from Au ion irradiation formats dislocation loops, whose distribution is influenced by subsequent He ion irradiation and He bubble formation. Samples irradiated with Au ions exhibit a shallow corrosion layer with big-size and dense distributed Cr2O3 particles, while a contrasting trend is observed in samples irradiated with He ions. Displacement damage decelerates Cr outward diffusion by promoting protective Cr2O3 formation with SO42- impurities, thereby inhibiting impurity-accelerated corrosion. However, the accelerating effect of He bubbles subsequently counteracts this inhibitory impact on corrosion. •Synergistic effect of ion irradiation and molten salt corrosion with impurity in GH3535 alloy was investigated.•Corrosion behavior was revealed by fine element distribution and microstructure characterization.•The inhibition mechanism of displacement damage on the accelerated corrosion by impurities was revealed.