The solidification microstructure and crystallization of Cr-Co-Mo-Ni bearing steel were simulated in solidification process based on CAFE methods in the electro-slag remelting process. The optimization of the intensity of cooling and molten pool temperature was simulated for Cr-Co-Mo-Ni bearing steel. The result shows that raising the cooling intensity to 7.5 m3/h and reducing the superheat temperature to 1600 can increase the grain nucleation number about 13.83%, and reduce the average columnar grain radius about 10.61%, to have a very good effect on refining the grains and get dense uniform solidification, which improve the homogeneity of the solidification structure, and reduce the performance differences of the materials.

Utilizing Pro-cast software, the whole vacuum arc remelting process of high-alloy bearing steel ingot (the diameter was 160 mm and the high was 600 mm) was simulated. And moving face quality and moving boundary conditions were added to the simulation. Purposes of the simulation were to explore the influence of smelting powers on the temperature field, pool shape and solidification microstructure in vacuum arc remelting process. The depth of molten bath gradually increased and stabilized finally and the pool shape transferred from flat to funnel. When smelting power increased, the depth of molten pool became deeper and the width of mushy zone slightly reduced; the size of primary dendrite and secondary dendrite spacing increased significantly; the percentage and size of columnar crystals also increased. A reasonable power-time cure was given to guide industrial melting after simulation, the size of molten pool morphology and microstructure were controlled in an ideal range under the reasonable cure. The simulated grain morphology agreed well with the experimental pickling result.

In this study, the temperature field distribution of 22CrMoH billet is first obtained by simulating continuous casting process using moving boundary method. On the basis of the above data, the microstructure of 22CrMoH gear steels billet was simulated based on CAFÉ (Cellular Automaton – Finite Element Analysis) method, together with the effects of alloying elements such as Cr, Mo, Si, Mn on the microstructure of this billet. The simulated result agrees reasonably well with that of the actual product. And it suggested that under the reasonable extend of current steel grade, the increased amount of Si and Mn can steadily widen the proportion of equiaxed grains, lead to the increase in equiaxed grain amount, hence the decrease in equiaxed grain average radius; The increase in Mo content is able to enhance the nucleation amount; Proper decrease in Cr content favors the increase in proportion of equiaxed grains, but little effects on grain’s amount and radius. Further, the composition of alloy elements under the specified scope of 22CrMoH grade was optimized and the simulated results showed that the microstructure has vastly improved, as the proportion of equiaxed grain rose nearly doubled, the grains amount has increased by 19.96%, and average radius has decreased by 9.20%.

An atomistic simulation is presented on the phase stability and lattice parameters of the new actinide intermetallic compounds A3Ni5Al19(A = Th, U). Calculations are based on a series of interatomic pair potentials related to the actinides and transition metals, which are obtained by lattice inversion method. Calculated lattice constants are found to agree with a report in the literature. It is noted that, the total and partial phonon densities of states are first evaluated for the A3Ni5Al19(A = Th, U) compounds. The analysis for the inverted potentials explains qualitatively the contributions of different atoms to the vibrational modes.

An atomistic study is presented on the phase stability, interatomic distances and lattice parameters of the new actinide intermetallic compounds AFe2Al10(A = Th, U). Calculations are based on a series of interatomic pair potentials related to the actinides and transition metals, which are obtained by lattice inversion method. The cohesive energy of AFe2Al10with two possible structures of YbFe2Al10-type and ThMn12-type are calculated and compared with each other. Calculated lattice parameters of AFe2Al10are found to agree with reports in the literatures. In particular, the phonon densities of states, vibrational entropy and Debye temperature related to dynamic phenomena are evaluated for the first time.