Vologda State Technical University

Main results are provided for development of a control program for coolant flow rate in the secondary cooling zone with steady-state and transitional steel casting regimes in a CBCM.The program makes it possible to visualize slab cooling and solidification, and to adjust the secondary cooling zone on the basis of readings of a pyrometer installed in one of the cooling sections.

The energetics and structural properties of native, substitutional and interstitial defects in NiAl have been investigated by first-principles methods.In particular, we have determined the formation energies of composition conserving defects and established that the so-called penta defect, which consists of four vacancies on Ni sublattice and Ni antisite on the Al sublattice, is the main source of vacancies in NiAl.We show that this is due to the strong Ni-site preference of vacancies in NiAl.We have also calculated the site substitution behavior of Cu, Pd, Pt, Si, Ti, Cr, V, Nb, Ta and Mo and their effect on the concentration expansion coefficientWe show the latter information can used for an indirect estimate of the site substitution behavior of the alloying elements.The solution energy of carbon and its effect on the lattice constant of NiAl have been obtained in the dilute limit in the first-principles calculationsWe have also determined the chem. and strain-induced carbon-carbon interactions in the interstitial positions of NiAl.These interactions have been subsequently used in the statistical thermodn. simulations of carbon ordering in NiAl.

A method is proposed for calculating coefficients of concentrational variations in lattice constants in solid solutions, based on first-principles determination of the total energy of solid solutions and the continual approximation in the solutions theory, allowing for the deformation interaction of impurity atoms due to distortions of the solvent crystal lattice.