Study On The Influence Mechanism Of The Impact Of Fluid Flowing From Submerged Entry Nozzle On Solidification Of Nb-Containing Steel Initial Solidified Shell In Crystallizer

Taking the casting billet in the continuous casting mold as the research object,the numerical simulation method was used to calculate and analyze the segregation behavior of the solute element in the two-phase region of the steel,and the high-temperature physical properties parameters in the two-phase region during the solidification process were calculated.The finite element software ANSYS calculates the temperature field of the billet shell in the mold,and simulates the change of the temperature field of the billet when its own and external conditions change.Based on Ueshima’s regular hexagonal dendrite solidification model,a solute permeation segregation model with coupled δ/γ phase transition was established by FDM.The analysis results show that C content is opposite to P,S,Nb and Ti elements are more obvious.When the concentration of C in the liquid phase is sufficient for the δ/γ phase transition,the proportion of the γ phase is increased,resulting in an increase in the degree of segregation of the elements P,S,Nb and Ti which are not easily soluble in the γ phase.The C content has a great influence on the high-temperature physical parameters of steel.With the increase of C content,the two-phase zone will be expanded,the change of solid phase ratio will be affected,the density will be reduced and the enthalpy will be increased.Because the high temperature physical parameters of steel with different solute components are quite different,it is not suitable to apply the physical parameters of different steels directly.By analyzing the temperature changes during the solidification of the slab under different physical parameters,it can be concluded that the temperature transfer inside the slab mainly depends on enthalpy and equivalent thermal conductivity.By applying a load to simulate the heat flow impact in the mold,The results show that high casting speed and high superheat make the surface temperature of the billet shell more sensitive to the molten steel in the mold.Figure32 Table11;Reference 49...