Mathematical Modeling And Experimental Study Of Hot Rolling Process On Plate Temperature Field

In the hot rolling process,the temperature distribution directly affects the rolling procedure including the rolling speed,rolling force,roll gap and other parameters.At the same time,the temperature also directly determines the internal structure of the steel plate.The difference of temperature often leads to differences in the performance of steel products.Most of the temperature monitoring in plate mills is mainly based on the values measured by infrared thermometer,which cannot directly provide reference for process control.In this work,the temperature field model of plate hot rolling process is established by numerical simulation,and the heat transfer coefficient is solved by experimental temperature combined with inverse calculation algorithm.It is applied to temperature model to improve accuracy,and then the temperature field inside plate is calculated accurately,which provides a basis for reasonable formulation of relevant process parameters.The main contents of this work are as follows:(1)Establishing a plate process model.A two dimensional heat transfer model based on width-thickness direction in hot rolling process of plate is presented in this work.According to the boundary conditions of air-cooled zone and deformation zone at different stages,different heat transfer coefficient models are adopted,and the governing equations are solved numerically by using finite volume method combined with initial conditions.The temperature field distribution within the steel plate with time is obtained.(2)Solving the heat transfer coefficient based on the inverse heat conduction algorithm.In this work,the characteristics of genetic algorithm,simulated annealing algorithm and particle swarm optimization algorithm are studied,and the inverse heat conduction problem models are established respectively.The inverse heat transfer coefficient in air-cooled zone is solved by combining the experimental data with the inverse calculation algorithm,and the parameters of heat transfer coefficient in hot rolling process are identified by selecting the optimal particle swarm optimization algorithm according to the solution situation.(3)Design and implement temperature test experiments.Through COMSOL software and DEFORM software,the rolling production scheme and experimental conditions are simulated respectively,which provides reference for the design of the experimental scheme and ensures the feasibility of the experiment.The experimental conditions are determined,the experimental samples are designed and processed,the temperature acquisition system is built and the experiments of rolling are carried out The temperature acquisition system collects the experimental data of temperature measuring points in real time.(4)Temperature field model accuracy verification and solution of parameter.For different stages of hot rolling process,the heat transfer coefficient obtained by empirical formula is modified by the inverse heat conduction problem model.The heat transfer coefficient after solving is substituted into the temperature field model of the positive heat conduction problem.The calculation accuracy is better than that of the original temperature model based on empirical formula.Comparing the temperature field data calculated and analyzed by the corrected temperature field model with the measured data,the error is less than 14?,which shows that the model has high accuracy and lays a good foundation for subsequent application research.