Effect of CrCl2 or VCl2 addition on corrosion of Cr metal in molten MgCl2-KCl

This study investigated the effects of adding 1 wt% CrCl2 and VCl2 on Cr corrosion in eutectic MgCl2-KCl at 773 K under an argon atmosphere, using electrochemistry and immersion experiments. The redox potential of V3+/V2+ was more negative than Cr2+/Cr, suggesting that V2+ can protect Cr from dissolution. Additionally, the morphological and chemical evolutions investigated with scanning transmission electron microscopy (STEM), energy-dispersive X-ray spectroscopy (EDS), and electron energy loss spectroscopy (EELS) confirmed the corrosion protection mechanism of adding CrCl2 and VCl2. These findings are crucial for further improving the stability of containment alloys in molten salt applications.