Study On Taper Theory Of High Speed Continuous Casting Mould

In the process of continuous casting,the crack defect of the billet in the lower opening of the mold is always the key problem to be solved affecting the quality of continuous casting billet.In order to solve this problem,it is necessary to carry out in-depth research on the taper curve of the mold and design a continuous taper curve with continuous optimization.In this paper,by simulating the solidification shrinkage process of the casting billet,the shrinkage deformation law of the casting billet was obtained.Based on this,the cross-section curve of the copper tube and the taper of the mould were studied and calculated.Finally,the mold cavity shape design method is obtained to reduce the crack defect of casting billet.Therefore,it is of great significance to study the mold taper.A two-dimensional unsteady heat transfer solidification mathematical model for casting billet has been established.The solid thermal conductivity differential equation is used to simulate the solidification and shrinkage process of casting billet by equivalence of the thermal conductivity of liquid phase and solid phase.In order to avoid the coupling of temperature field and stress field,the given average heat flux form was selected when the heat transfer boundary condition of the interface between the billet and the mold was set.At the same time,the mathematic model of shrinkage deformation of billet shell was established by thermodynamic coupling method.By analyzing the influence of casting steel type,billet speed and cooling condition on the mold taper design,the taper suitable for the billet and the longitudinal section curve expression of the inner wall copper tube were calculated.On this basis,taking 150mm×150mm billet as the research object,the heat transfer and solidification shrinkage process of the billet were simulated by using the established finite element model,and the temperature distribution of the billet in the mold and the solidification shrinkage rule of the billet shell were obtained.Through the analysis and study of the temperature field and shrinkage deformation of the billet,the calculation expression of the cross section curve of the copper tube and the solution method of the shape of the inner cavity of the copper tube in the mould are obtained.The expression of cross section curve of copper tube and the method of calculating the shape of inner cavity of copper tube in mould are obtained.At the same time,the influence of mould corner shape on the heat transfer effect was studied,and the Angle of mould corner was changed to a certain Angle of arc Angle to improve the heat transfer.Finally,according to the data obtained from the simulation calculation,the section curve size and mold taper of 150mm×150mm square billet mold were solved.