Taking into account the electrochemical activity of chloride salt melts, the available experimental data are analyzed and the fundamental regularities of the corrosion-electrochemical behavior of nickel-based metal materials in molten halide salt electrolytes are revealed. Special attention is paid to the relationship between the composition of materials, their properties, the quality of the interface, the characteristics and possible methods of protection against corrosion. When reprocessing spent nuclear fuel from a fast neutron reactor (SNF FRN), LiCl–KCl melt (0.49 : 0.51) is used in an inert atmosphere, all metal materials in this salt melt are extremely susceptible to corrosion, moreover, in the process of SNF reprocessing as a liquid (melt), and the gas phase are saturated with fission products, which can act as additional oxidizers, increasing the aggressiveness of the medium. The corrosion behavior of nickel, as well as alloys based on it (Ni–Cr and Ni–Ti) in a salt melt of lithium and potassium chloride, containing as an additive from 0 to 5 wt % lithium oxide Li2O and cerium trichloride CeCl3. The experiments were carried out at a temperature of 500–700°C in an inert argon atmosphere for 24 h. It was found that the corrosion rate increases in the following order: Ni < NiCr < NiTi. With increasing temperature, the corrosion rate of the material increases significantly for each material studied. According to the combined data of gravimetric, X-ray microspectral, and atomic emission spectral analysis, it was established that the main cause of corrosion is the presence of oxygen-containing impurities (O2) in the gas atmosphere above the melt and/or in the salt electrolyte. These impurities mainly react with the electronegative components of the alloy – Ti, Cr, with the formation of their oxides of non-stoichiometric composition, which is enhanced by the introduction of lithium oxide into the melt due to an increase in the concentration of the O2-anion. The introduction of cerium trichloride into the melt leads to the formation of a stoichiometric cerium oxychloride layer on the surface, which in turn reduces the corrosion rate due to surface passivation and a shielding effect; with increasing temperature, this effect is observed to a much lesser extent.