[en] A wear-resistant steel is developed not requiring chemical-heat treatment (CHT) (carburizing, carbonitriding) used for aircraft engineering units. The new steel has double the level of wear resistance than that with CHT. The cast steel optimum phase composition is determined guaranteeing good wear resistance. It is established that the amount of carbide phase in solid solution may be ≥ 8.5 wt.%, and 90% of carbide is based on vanadium. In order to obtain the required level of steel properties not less than 0.35 wt.% chromium, and 0.5 wt.% vanadium should be in solid solution. The amount of residual austenite is not more than 15%.

[en] Chemical reactions between small carbon molecules up to C₅ in rapidly expanding pure carbon vapour are considered under the assumption of translational equilibrium. The equilibrium between translational and internal degrees of freedom of molecules (vibrations and rotations) is not implied. To take into account the difference between the translational and internal temperatures, the conventional equations of chemical kinetics are complemented with energy balances. Numerical calculations are made for the expansion dynamics, typical for graphite ablation by 25 ns laser pulse at the target temperatures from 2500 to 6000 K. The translational part of internal energy of vapour rapidly decreases at expansion and a large gap between translational and internal temperatures arises after about 10^-6-10^-5 s. Translational temperature becomes very low and internal temperatures of C₂ to C₅ molecules remain as high as 2000-3000 K. The molecular composition calculated at the target temperature of 2500 K qualitatively agrees with experiments and is characterized by a high fraction of C₃ molecules. In the range 4000-6000 K, molecular composition depends weakly on the temperature. The fraction of C₃ remains high. The fraction of C is less and the fraction of C₅ is significantly higher compared with the case of 2500 K