Ansys-based Numerical Simulation Of Billet , S Temperature Dropping And Thermal Stress In Secondary Cooling Zone

Finite element method is a more sophisticated numerical simulation, and with the constant upgrading of computer software, and gradually used in various areas of engineering, The objective of this thesis is to investigate its usability for calculating the solidification and thermal stress of solid shell in continuous casting mold.Physical and chemical phenomenon which is complicated in thousands of high temperature is involved in continuous casting, and there have not been effective means for field experiment. Many researchers are very difficult to analyze the changes in temperature and stress .So ,the numerical simulation is supposed to be the best means to research on the behavior of the flow and heat transfer and optimize continuous casting process in the continuous casting mould by using mathematical mold plays an important role in the study of this front field ,which can offer basis in theory for control of industrial yield and mould design of secondary cooling zone when the features of steel liquid flow and the distribution of the stress are known.Based on the practice of continuous casting machine, using finite element software ANSYS, this thesis established a thermal stress model in continuous casting process. In order to analyze continuous casting process and stress exactly ,this model takes the variations of material properties with temperature into account , reasonably considers the exact geometry of the Billet corners , and also studies the influence of casting speed ,degree of superheat , specific water flow of secondary cooling zone on stress distribution ,and the corner radius of the billet.The result showed that the features in the mould were exactly reflected by the mathematical model represented, and it was effective that some equations were modified, and the constant and boundary condition adjusted, such as Poisson's ratio, coefficient of thermal expansion and so on. At the same time, the basis that studies the problem of metallurgy engineer on heat, force and flow using ANSYS was done.The simulation results indicate that thermal stress is the main reason for all the cracks. Internal cracks location of numerical simulation in the Billet with the actual location of the corner crack and leak within the site of steel is basically consistent. Slab corner gap significantly reduces the efficiency of heat transfer surface of the solidified shell. It makes a greater stress concentration in the second cool zone when the slap is further solidified, resulting in much bigger possibility of corner-crack. Fixed in the specific water flow of secondary cooling zone and increasing casting speed within a certain range,the maximum thermal stress decreases,which reduces the possibility of crack. Fixed casting speed, increasing specific water flow of secondary cooling zone enhances the angle thermal stress on the surface and has less impact on thermal stress of the corner. Compared to the specific water flow of secondary cooling zone, casting speed has great influence. Degree of superheat and the corner radius of the billet have little effect on the Stress,which show little effect on internal crack, but the latter is able to control the corner position of internal cracks.