Numerical Simulation On The Temperature Variation Of The Continuous Casting Billet During The Transporting To The Direct Rolling Process At Hanzhong Iron & Steel Ltd.

Continuous casting direct rolling is an important energy-saving technology.Recent years,with the iron and steel industry facing increasingly severe challenges,the technology trends to be attracted the attention of the word's iron and steel enterprise.It is a basis for the application of continuous casting direct rolling to accurately master the temperature distribution during the cooling process of continuous casting billet.In order to solve the interlinking problem between the temperature and velocity of the continuous casting billet in continuous casting direct rolling,the 150mm×150mm continuous casting billet of double high line-1# continuous casting direct rolling line obtained from the Hanzhong Iron & Steel Group Company was taken as the research object in this paper.Based on the heat transfer mechanism and the idea of finite thickness thin layer(continuous casting billet moving along the casting direction),unsteady heat transfer model of 2D continuous casting billet was built by using ANSYS to study the temperature change of continuous casting billet.The distribution of the temperature and the shell thickness in the exit of the mold,as well as the secondary cooling zone and the air-cooled zone were analyzed in detail by numerical simulation.Besides,the influence of different casting temperature,the secondary cooling zone water,the casting speed and casting billet chamfering on the cross section temperature of casting billet are also analyzed.The results show that with a increases of 5°C for the casting temperature,the average temperature of the billet cross section increases about 11°C.However,when the secondary cooling zone water increased,the liquid core temperature of the billet was decreased,so the surface center and the corner temperature,which e nabled the thickness o f billet shell increased by 1.5mm.But it had little effect on the liquid core length.Besides,when the amount of water is increased by 0.2L·kg-1,the average temperature of the billet cross sect ion will be reduced by about 25°C.The casting speed is going to be increased by 0.2m·min-1,the effective average temperature of the billet center w ill be increased by about 20~30°C,the average temperature of the billet surface will be increased about 15~25°C,and the average corner temperature will be increased about 10~20°C.The billet shell thickness was reduced about 0.4~5 mm and the average depth of liquid po int depth increased about 0.1~1 m.The right angle,equilateral angle,no equilateral angle and fillet of the billet in the mold and cut-off point center temperature and the lowest corner temperature were analyzed.The results show that right angle corresponding to both the central temperature and the lowest corner temperature is the lowest in the mold and cut-off point,other chamfered shapes have a negative effect on the reduction of temperature,and the fillet of the billet has the greatest inhibitory effect.In addition,on the uniformity of temperature,the continuous casting billet is obviously better than that of the right-angle billet.In the comparative analysis of the measured temperature and the simulation results in the billet production process,there are some errors between the results of simulation and the measured results,but the overall trend is consistent,which proves the accuracy of the finite element model and simulation results.Therefore,it has important theoretical significance for the realization of continuous casting direct rolling in Hanzhong Iron & Steel Group Company to use numerical simulation to grasp the temperature change of continuous casting direct rolling.