This article presents a review of current results of theoretical and experimental studies of the specific features of the structure that is formed in high-strength low-alloy steel in the process of hot rolling and which determines the properties of the steel. The current concepts of the physical processes that are developed at different stages of a thermomechanical treatment depending on the temperature–strain-rate regimes and chemical composition of the steel are considered. Particular attention is paid to the problems of the formation of the structural state that continue to be debated. The simulation methods of different scale level used to solve the problems of controlling structure formation at all stages of thermomechanical processing process are discussed.
Using methods of statistical kinetic theory parametrized with first-principles interatomic interactions that include chemical and strain contributions, we investigated the kinetics of decomposition and microstructure formation in Al-Cu alloys as a function of temperature and alloy concentration. We show that the decomposition of the solid solution forming platelets of copper, known as Guinier-Preston (GP) zones, includes several stages and that the transition from GP1 to GP2 zones is determined mainly by kinetic factors. With increasing temperature, the model predicts a gradual transition from plateletlike precipitates to equiaxial ones and at intermediate temperatures both precipitate morphologies may coexist.
Thermodynamics and atomic structures of pre-precipitates in dilute Al–Cu alloys are studied using Metropolis Monte Carlo simulations with many-body effective cluster interactions that have been systematically derived from ab initio supercell calculations. We show that many-body interactions, including the contributions due to lattice relaxations around the solute atoms, are mainly responsible for the formation of metastable planar atomic arrangements known as Guinier-Preston zones. Interaction terms up to four-body clusters are shown to be necessary to correctly reproduce the structures and temperatures of pre-precipitation in Al–Cu solid solutions.
The article contains computational data of many-body interactions in Al-Cu alloys, obtained using PAW-VASP calculations. Pairwise, three-site, and four-site interactions are presented. Mentioned data are relevant to the research article "Many-body mechanism of Guinier-Preston zones stabilization in Al-Cu alloys" (Gorbatov et al., 2017) [1].
