Abstract
This work is devoted to the study of changes of structure and chemical composition of two candidate materials for high-temperature power engineering. Materials are studied before and after their exposure to molten mixture 60 mol.% LiF + 40 mol.% NaF at temperature 953 K for exposure times 100, 300 and 1000 h. The exposition was carried out in a quasidynamic regime that simulated the flux of the coolant (the mixture of salts) in the pipeline. In Ni-alloy Ni-6 W-9 Mo-1.7 Ti-7 Cr (wt.%) severe corrosion damage was observed in the surface layer of thickness of about 100 µm. In Ni-coated ferrite steel CSN 411523, elements redistribution close to the interface between the Ni layer/steel substrate was described by a simple model. The Ni layer showed excellent resistance against the corrosion, but its perforation and subsequent local damage of the substrate were also observed.

Key words
steels, nickel alloys, corrosion, diffusion, coating

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