Research On Heat Transfer Law Of Hot Rolled H-beam During Controlled Cooling

The numerical simulation of hot-rolled H-beam controlled cooling process has made great progress after long-term development.However,there are still many complicated problems in theoretical research and industrial application: during the heating and cooling process,the surface and medium,The surface heat transfer coefficient is influenced greatly by the working condition.The workpieces and the cooling medium are in different states,and the contact ways are different.Even the same part has different surface heat transfer coefficient.How to accurately determine the comprehensive heat transfer coefficient of the surface is of great significance to improve the accuracy of numerical simulation of H-beam heating and cooling process and to control and ensure the rolling quality of H-beam.In this paper,a lumped parameter method and finite element Ansys simulation are used to verify that the cylindrical Q235 probe conforms to the one-dimensional transient heat transfer and ensures that it is consistent with the one-dimensional transient of the H-shaped steel.Secondly,The experimental data of temperature near the surface are obtained by heating and three cooling methods(water cooling,air cooling and spray cooling).The real data files are obtained by real color paperless recorder and instrument management software.The data are imported into Matlab and the experimental data are fitted.The method of non-linear estimation is obtained by using iterative programming with Matlab software;At last,the finite element model of the temperature and the temperature field of the heating and cooling process are established by using Ansys finite element software.The heat transfer coefficient is verified by the experiment data.The model takes into account the influence of the factors such as thermal properties,latent heat of phase change and kinetics of phase transition.And the change of temperature field and stress field along the path are taken to study the change of temperature field and stress field of the new H-beam based on the experimental data.The research on the rule of controlled cooling and heat transfer after H-rolling is a key problem to further improve the accuracy and level of numerical simulation of cooling control.With the development of national economy and the rational utilization of resources,the new technology of cold control will be used to reform the traditional profile production technology,and it has a very real and far-reaching significance.