High Precision Temperature Setting Up And Application In Plate Rolling Process

Temperature is an important parameter in the plate rolling process. Temperature affects the calculation of force, so predicting the temperature precisely of every phase is the key of the control of thickness, width, and the shape of plate. On the other side, temperature is also useful to the prediction of microstructure. In the past, temperature compute models can not adapt the change of environment and are not precise because of the disadvantage in theory or the simplification. Therefore developing a precise temperature model is meaningful.As a numerical value computer method, finite element method (FEM) can calculate the temperature field of plate precisely. In the past, because of the restriction of the compute time and the oscillation phenomenon in FEM calculation process, online application was restricted. As the development of the theory of FEM and the appearance of some fast FEM theory, it is becoming possible to calculate temperature in rolling process in FEM.Two-dimension temperature mathematics model is developed in plate rolling in FEM based on the theory of heat transfer. This model can calculate the temperature of every node of transect of plate at random time, and present the average, central, and surface temperature. An online application scheme of FEM mathematics model is proposed based on a plate production line, and the aim of online application is finally realized. The main contents are as following.(1) A temperature calculation model of plate rolling process is developed, the boundary condition of the phases of air cooling, descaling, and rolling, the temperature increase for the distortion of plate in rolling, and the change of thermo-physical parameter are took into account.(2) Calculation precision problem is considered by analyzing the effect of iterative time of every phase in rolling, the number of element, the temperature increase for distortion, and the phase change to the calculation result.(3) The reason of numerical oscillation is analyzed, and several methods are researched to restrain or avoid oscillation.(4) Calculation time problem is considered by researching the effect of iterative time, the number of element, thermo-physical parameter calculation model, and so on.(5) Online application of FEM is realized. Combined with the plate production and process control system, an application scheme is proposed, and FEM temperature model is finally applied in plate rolling.