Corrosion behavior of three nickel-based single-crystal superalloys in mixed Na2SO4 and NaCl molten salts at 700 ℃

• The corrosion mechanism of nickel-based single-crystal superalloys in mixed Na2SO4/NaCl molten salts at 700 °C involves cyclic oxide layer formation and decomposition, leading to a protective NiO layer with a regenerating Al2O3 barrier. • Alloying elements Cr, Al, Ta, and particularly Re significantly improve thermal corrosion resistance, providing strategic directions for alloy composition design. • Gibbs free energy calculations of corrosion products help elucidate the influence of alloying elements on corrosion performance, enabling predictive insights for material selection. • The findings enhance understanding of low-temperature hot corrosion (600–750 °C) mechanisms, critical for aerospace and energy applications where superalloys face aggressive salt environments.