1. For the practical application of the alloy MA21 it is most favorable if it has a fine-grained quasieutectic structure obtained in continuous laser treatment. 2. Between the power density of the radiation, the geometry of the laser track, the corrosion rate, and the volume fraction of α-phase in the alloy MA21 there exist empirical correlations. 3. The permissible temperature interval to which the alloy MA21 may be heated in irradiation is ΔTp=60–70°C. 4. To eliminate the effect of nonsteady fluxes on the process of eutectic crystallization in CLHT in air, the wall thickness of parts must not be less than 30 mm. 5. A method of engineering calculation of the critical mass of the irradiated part was worked out: with it the parameters of the technological process of CLHT in air can be evaluated.