The Numerical Simulation Of Flow Distribution Process In Twin-roll Casting

Twin-roll casting is a near-end continuous casting production technology,which has the advantages of short production process,low investment,energy saving and environmental protection.At present,this technology has been widely used in the casting and rolling production of magnesium,aluminum alloys and thin strip steels.As an indispensable deoxidant,inoculant and elemental additive in iron and steel smelting,the production method of ferroalloy has been a hot topic at home and abroad.However,there are few researches on the twin-roll casting technology of ferroalloy at present,and the technology is not yet mature,and further research is needed.Among them,the flow pattern of the flow distributor is the key factor affecting the product quality.It is of great significance to discuss the influence of various parameters of the twin-roll casting flow distributor on the flow field and temperature field of the molten pool.In this project,a laboratory twin-roll casting mill is used as a prototype,and a fluid-solid-thermal coupled numerical model for twin-roll casting is established on the basis of considering flow distributor,roll sleeve,molten pool,material nonlinearity and complex boundary conditions.And use ANSYS CFX software to study the distribution law of the flow field and temperature field of the molten pool,and analyze the structure parameters of different flow distributors,including the side opening inclination,opening height and opening width,end opening height and opening width,and the length of the flow distributor.And immersion depth and different process parameters,including the influence of pouring temperature and casting and rolling speed on the thermal coupling field of molten pool flow.The results show that the flow velocity and temperature of molten metal at different positions in the molten pool are different,and there are also large differences in the degree of influence of the structural parameters of the flow distributor on the thermal coupling field of the molten pool and the rules of influence.By analyzing the influence of each structural parameter change of the flow distributor on the flow distribution one by one,a recommended parameter value is obtained which is most conducive to ensuring the quality of the strip.Through orthogonal optimization of the structural parameters of the flow distributor,the optimal structure parameter combination was obtained by using the turbulent kinetic energy difference on the surface of the molten pool and the temperature difference at the outlet of the molten pool as the evaluation index,and the simulation model was re-established for calculation and simulation with the originalmodel The comparison of results verified the correctness of the optimization results.Later,through comparative analysis,the side opening width was determined to be the factor that had the greatest influence on the thermal coupling field of the molten pool flow,and its influence was studied in detail.Finally,based on the optimized flow distributor structure,the effects of the pouring temperature and casting and rolling speed on the flow field and temperature field of the molten pool were analyzed,and the optimal process parameters were obtained: the casting temperature is 1800 K and the casting and rolling speed 3m/min.