An influence of gas phase composition, its dependence upon ratio of initial substances and temperature on saturation efficiency of Al and Cr powders is studied. Adsorption and diffusion of these elements on to surface of nickel alloys (ZhS6U, ZhS26) are executed in the closed chamber of circulation unit at certain temperature (1000-1400 K). Thermodynamic calculations show the possibility of deposition of the Cr-Al coating in chloride medium. The mechanical and thermal properties of coated alloys are discussed.