Study On The Solidification Process Of Continuous Casting Slab And Its Application In Optimization Of Secondary Cooling

Continuous casting of steel is the technology of casting the molten steel to forming continuously.Continuous casting of steel is energy-saving and high efficiency.It is widely used in metallurgical industry.Continuous casting of steel is the process of the solidification of molten steel.The use of the cooling water to control of the solidification process is the key technology.In this paper,the solidification process of continuous casting slab in the carbon steel slab continuous casting machine in North China is studied.The statistic show that more than sixty percent defect of the slab related the crack.The paper uses the thermal simulation testing machine to simulate a continuous casting machine of steel production of thermal process to obtain the yield strength and tensile strength,section shrinkage temperature mechanical performance indicators such as the variation with temperature.It is useful to the secondary cooling operations.The test is effective to prevent various slab cracks.The continuous casting slab solidification model of Q235 and Q345 was built on the basis of the carbon steel continuous casting machine in North China.The general formula is proposed to calculate the thickness of the casting.Different temperature nephogram of casting speed in different position were drawn by controlling the slab surface temperature and the core temperature to derive the optimal slab solidification shell growth curve.The model of secondary cooling was built.Considering the specific situation of the equipment,the cooling zones are reasonable planning.Most important secondary cooling equipment is the nozzle.The water nozzle and two air-water nozzle were tested.Air-water nozzle's most important parameters are the average droplet size and droplet size distribution.This article has been tested on a variety of nozzles compared to study its in the best operating conditions for equipment selection and process optimization.After summarizing the structure and technological parameters of the slab caster,a heat transfer mathematical model of continuous casting slab was established.The continuous casting process was simulated by using the heat transfer model.The change laws of temperature field and solidification in different conditions were obtained by simulating.Combined with the results of shooting nail tests,the rationality of secondary cooling system were analyzed respectively.The results show that secondary cooling systems can satisfy the requests.