Effect of Surface Decarburization on Corrosion Behavior of GH3535 Alloy in Molten Fluoride Salts

• Published in: Acta metallurgica sinica : English letters Vol. 32; no. 3; pp. 401 - 412
• Main Authors: Hou, Juan, Han, Fen-Fen, Ye, Xiang-Xi, Leng, Bin, Liu, Min, Lu, Yan-Ling, Zhou, Xing-Tai
• Format: Journal Article
• Language: English
• Published: Beijing The Chinese Society for Metals 01.03.2019; Springer Nature B.V
• Subjects: Alloys; Characterization and Evaluation of Materials; Chemistry and Materials Science; Concentration gradient; Corrosion and Coatings; Corrosion effects; Corrosion resistance; Corrosion tests; Decarburization; Decarburizing; Fluorides; Grain size; Graphite; High temperature; Iron; Materials Science; Metallic Materials; Microscopy; Microstructure; Nanotechnology; Nickel base alloys; Nuclear reactors; Organometallic Chemistry; Oxidation; Spectroscopy/Spectrometry; Spectrum analysis; Superalloys; Tribology; Ni-based superalloys; Decarburization; Corrosion; Molten salt
• ISSN: 1006-7191; 2194-1289
• DOI: 10.1007/s40195-018-0814-5

Corrosion test of a Ni–16Mo–7Cr alloy with a decarburized layer was conducted in FLiNaK salt at 700 °C. A detailed microstructure study was performed to investigate the corrosion behavior and mechanisms. The results show that the Fe-rich layers were formed on the corroded alloys with and without decarburization. The surface decarburization had little influence on the corrosion resistance of the alloy, whereas it caused more M 2 C carbide formation beneath the corrosion layer. That is attributed to the higher concentration of C gradient near the alloy surface, which was resulted from the increase in C content liberated from graphite crucible wall during the corrosion process.