| The paper reviews the deterministic model—stochastic model— phase-field model development and techniques of microstructure simulation of metal solidification process, as well as shortcomings for various models, argues that the Cellular Automation stochastic model suits to simulate microstructure evolvement of solidification process in the heated mould continuous casting(HMCC) as the model involves the preferential direction of crystal growth, with its obvious physical setting.The experiment studies the mechanism of microstructure evolvement and brings forward the three stages of structure evolvement in solidification process: 1) rapid selective elimination of crystal articles, 2) slow selective elimination of crystal articles and 3) single crystal growth. Structure evolvement lies on the shape of liquid-solid interface. Protruding liquid-solid interface is propitious to the selective elimination of crystal articles, gaining single crystals. And the shape of liquid-solid interface rests with casting speed, varying from convexity to plane to concave with the increase of it.Monte Carlo method can simulate structure formation process of unidirectional solidification, demonstrating the competitive growth of column-shaped crystals in unidirectional solidification, and the simulation result is definitely similar to the actual structure. Monte Carlo method, devoid of specific physical basis, however, does not touch upon some key parameters in unidirectional solidification such as the preferential direction of crystal growth. Still, Monte Carlo Method can be used as qualitative simulation technique for structure formation in unidirectional solidification, with the supply of definite reference value for the analyses of various technical parameters.With displaying alternative difference numerical method of heat transfer process and Cellular Automation of microstructure simulation, a combinative macro-microcosmic 2D and 3D coupling model of microstructure simulation can be established by couplingmacro temperature field simulation with microstructure simulation. With pure metal Cu as a subject, this model technique is used to work over its (Cu) structure evolvement process and to test the effect on it of various technical parameters. The research indicates that 2D simulation results come to reflect the characteristics of structure evolvement as does HMCC process and appear to better accord with actual experiment results. On the other hand, 2D simulation results can show microstructure in the transect of casting road only and cannot well and truly reflect the process of structure evolvement due to the dissymmetry and randomness of microstructure. Even more true simulation is not only to show microstructure in the vertical section, but of microstructure transect, so there must be great necessity of carrying out 3D simulation, with which the evolvement in the HMCC process can be completely and truly described and shown. 3D microstructure simulation can display and reproduce crystals. Simulation research of structure evolvement at different technical levels in HMCC indicates that the casting speed has obvious effect on liquid-solid interface concerning its shape, position and competition of crystals growth. With the increase of casting speed, liquid-solid interface changes from convexity liquid appearance to smooth plane, even to convexity solid appearance, and the higher the mould temperature is, the stronger the competition of crystals is. While cooling intensity has not too effect on the competition of crystals, higher mould temperature and corresponding stronger cooling intensity can get casting road with smooth surface and not to be pulled leak and part in casting process. Cellular Automaton Model for simulating microstructure formation has specific physical property, with the simulation result very adjacent to the true situation, which convincingly makes clear that Cellular Automaton Model is a feasible simulation technique for microstructure simulation.
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