Precise Simulation And Control On Temperature Field Of Continuous Casting Billet Of Hot Direct Rolling

Intelligent manufacturing and green manufacturing are the two major development directions of the steel production process industry.The hot direct rolling technology of continuous casting billet,which is different from the traditional continuous casting-heating-rolling production process,meets the requirements of green manufacturing and greatly reduces energy consumption.The implementation of intelligent manufacturing on this new process requires accurate perception of the parameters of the production process,and one of the most important parameters is temperature.In this paper,a non-heating straight-rolled wire rod production line of a steel mill in Guangxi is the research object,and the finite element software ANSYS is used to establish an unsteady heat transfer model.The solidification process of the continuous casting billet and the heat preservation and transportation process after the billet shear are simulated and calculated.Experiments verify that the casting speed and uniform temperature process parameter adjustment schemes that have guiding significance for actual intelligent production are proposed,which lays a theoretical and practical foundation for improving quality.(1)In order to prevent the occurrence of breakout at the exit of the mold and breakout at the cutting point,a prediction model for the temperature of the billet,the thickness of the billet and the position of the solidification end point was established.For the first time,the temperature distribution of the cross-section of the billet after shearing was used as a basis to verify the agreement between the numerical simulation temperature field and the real temperature field of the billet,avoiding the traditional use of surface temperature as the accuracy of the inspection result and the large deviation from the actual result.The results show that the relative error deviation between the two is 1.8%,and the agreement is relatively high,which shows the reliability of the simulation data and truly reflects the three-dimensional temperature field of the billet.(2)On the basis of accurately predicting the temperature field,without changing the cutting position of the billet,a water volume ratio model for the secondary cooling zone with the minimum safe distance from the cutting point as the goal was developed.According to the calculation results of this model,high-speed continuous casting can be appropriately used under the same conditions as existing equipment.The maximum drawing speed of the billet can reach 3.09 m/min,which is 15.3% higher than the original drawing speed of 2.68 m/min.(3)Aiming at the phenomenon that the large temperature difference between the head and tail of the billet in actual production leads to the large difference in the performance of the product cleaning rod,the influence of the insulation cover on the conveying roller table after the billet cutting on the temperature field of the billet is studied,and its length,The influence of parameters such as holding time and additional positions on the temperature difference between the head and tail of the billet.The results show that reasonable adjustment of the process parameters can control the temperature difference between the head and tail of the billet within 30 ?,which can better meet the temperature requirements of the heating-free direct rolling technology of the billet.The temperature field of the transportation process was verified on site,and the maximum relative error between the simulated and measured results was 1.7% to meet the production requirements.