High-temperature corrosion behavior of Ni–16Mo–7Cr–4Fe superalloy containing yttrium in molten LiF–NaF–KF salt

Highlights: • Traces of yttrium were doped in Ni–16Mo–7Cr–4Fe nickel-base superalloy. • High-temperature corrosion resistance is improved by proper yttrium addition. • Synchrotron radiation X-ray fluorescence with high sensitivity was adopted. - Abstract: The corrosion tests of a Ni–16Mo–7Cr–4Fe superalloy containing various yttrium contents were performed in molten FLiNaK (LiF–NaF–KF: 46.5–11.5–42 mol%) salt at 850 °C for 620 h, with the goals of investigating the effects of yttrium on the corrosion resistance of Ni–16Mo–7Cr–4Fe alloy and understanding the corrosion mechanisms. The addition of an appropriate amount of yttrium promotes the formation of a Y-rich layer near the surface and inhibits the diffusion of the susceptive elements