The Soft Measurement About Temperature Distribution Of Twin-roll Casting Molten Pool

In recent years, twin-roll casting process of steel strip, as a new technology representing the development direction of steel industry, attracts the world-wide attention of the steel researchers. Improvement is still in great need to realize the industrial application. The keys of producing high quality thin strip are the metal flow in the pool and the tundish, the heat transfer behavior and the solidification of the molten steel in the twin-roll casting process. In the present work, the twin-roll strip casting process was numerically simulated. The heat transfer behavior and the solidification of the molten steel in the twin-roll casting process was investigated systematically. The results have significant influences in theory and practice on industrialization of the twin-roll casting process. Significant processes and innovative research results have been obtained, which are as follows:(1) Heat transfer characteristics of the molten pool were analyzed by using heat transfer theory and the boundary of the molten pool conditions was confirmed. In addition, methods for dealing with latent heat of solidification and the heat transfer coefficient between the pool and the casting roller were raised.(2) According to the geometrical characteristics of the research object of this thesis and in the combination with the influence factors of the finite element mesh generation, the principles of mesh were established. Entity model was divided by 8-node hexahedron units and a new quality improvement technique combined topological optimization and node position smoothing was proposed for improving the quality of grid.(3) The weighed residual method of Galerkin is used to develop the variation equation of 3D transient-state temperature field. The running speed and the accuracy are extremely improved after simplified the calculation formulas of stiffness matrix and heat capacity matrix. The methods of dynamic time step and lumped heat capacity matrix were introduced to resolve the numerical oscillation problem.(4) According to the above mathematical model, program which can simulate the transient-state of 3D temperature fields have been wrote using MATLAB language. Compared with the simulation value of ANSYS, the results showed good agreement by difference lower than 2%.