Corrosion of SiC induced by Hastelloy N alloy and its corrosion products in LiF–NaF–KF molten salt

• Effect of Hastelloy N alloy and corresponding corrosion products on the corrosion of SiC was studied.
• Ni in alloy can react with Si in salt to drive the corrosion of SiC by the formation of Silicide (Ni31Si12, NiSi,) on alloy.
• Corrosion product NiF2 can increase the corrosion of SiC. Raman spectrum indicates that Si in salt is in the form of [SiF6]2−.
• Corrosion product CrF2 can drive the corrosion of SiC by the formation of carbide (Cr7C3, CrC) on SiC.

Interaction between SiC and Hastelloy N alloy in LiF–NaF–KF salt was studied for the application of SiC to molten salt reactors. Results reveal that Hastelloy N alloy and its corrosion products can induce the corrosion of SiC in salt. Ni can react with Si in salt to form silicide (Ni31Si12, NiSi). Cr2+ can react with SiC to form carbide (Cr7C3, CrC). Ni2+ can cause SiC with a thickness of 50 μm almost disappear after 45 days; thus, the Si content in salt can increase to 0.5 wt%. Raman spectrum indicates that Si in salt is in the form of [SiF6]2−.