[en] Kinetics of growth, structure and composition of intermediate phases resulting from reaction between WSi₂ coating and the W substrate (in the presence and in the absence of barrier sublayer tungsten borides at 1300-1800 deg, and the performance of such coatings in air at 1500-1850 deg have been studied. The WSi₂ coating has been studied by metallography and by micro-X-ray-spectral analysis. Annealing of WSi₂ coating on W at 1300-1800 deg C is found to cause reaction between W and WSi₂ resulting in a lower silicide W₅Si₃; annealing for 2 hours at 1800 deg causes complete conversion of WSi₂ into W₅Si₃ in a layer 100-110 μ thick. The thickness of the W₅Si₃ layer grows according to a parabolic law. Preliminary boronation of tungsten prevents formation of lower silicide phases and decreases the rate of WSi₂ layer growth approximately twofold. Annealing of such a coating leads to formation of a W₂B phase at the W-WB boundary, and to formation of a complex phase Wsub(x)(B,Si)sub(y) at the WB-WSi₂ boundary. The WSi₂ coating reliably protects W from oxidation for 5-10 hours at 1600-1850 deg C, for 3-5 hours under conditions of cyclic temperature variations, and for >=0.1 hour under pulse impact of temperature. Introduction of a boride sublayer under the WSi₂ coating increases its life under the conditions studied by a factor of 1.5 - 2