棒材穿水冷却工艺及其实验研究

发布时间：2018-11-18 08:38

【摘要】：随着对新型棒材质量及性能的要求越来越高,棒材的控冷工艺也相应的更加精确。通过控制棒材水冷过程的温度变化,可显著改善棒材内部组织,得到更好的晶粒,提高棒材的强度和韧性。因此,研究棒材水冷过程的温度变化有着重要的意义。本文利用有限元软件建立了棒材水冷过程的数值模型,在改变入水水压及入水角度的条件下,系统研究棒材冷却时温度变化的影响规律;通过对比分析并结合现场生产工艺,获取了较优的控冷参数;以理论研究为基础,设计了一套棒材穿水冷却实验平台;通过现场实验对模拟得到的结果进行验证。主要研究内容如下:首先,建立冷却管和棒材的计算流体学模型。借助流体模拟软件FLUENT,研究棒材水冷过程中,流体流动状态及棒材的温度变化。通过模拟可知,流体在经过冷却管的收缩区和扩张区时,因速度差的原因会发生紊流,由于局部的紊流会打破冷却水和棒材产生的蒸汽膜,使得棒材表面与冷却水充分接触,提高冷却效果。同时,对棒材温度场分析可知,棒材在冷却水冲击过程中,表面的温度会急剧下降,当下降到一定温度时,棒材的温度将趋于一定值。其次,在改变水压及入水角度的条件下,模拟棒材冷却过程中温度的变化。相同时间里,入水水压对棒材的温降影响很大,而角度影响较小,但角度设置过高反而会对棒材的降温有一定的阻碍。通过模拟得到的数据,选择合适的入水水压及角度,为下文建立棒材穿水冷却实验平台奠定基础。然后,设计了包括加热、输送、冷却棒材的实验平台。设计确定了电磁感应加热器的加热频率、电源功率及线圈匝数;并计算选择了输送辊道及其电机。最后,通过棒材穿水冷却的现场实验验证了棒材穿水冷却模拟的结果有较高的可信度。
[Abstract]:With the higher quality and properties of the new bar, the cooling control process of the bar is more accurate. By controlling the temperature change of the bar during the water-cooling process, the internal structure of the bar can be significantly improved, better grain can be obtained, and the strength and toughness of the bar can be improved. Therefore, it is of great significance to study the temperature change in the process of bar water cooling. In this paper, the numerical model of bar water cooling process is established by using finite element software. Under the condition of changing the water pressure and angle of entry water, the influence law of bar cooling temperature is studied systematically. Through comparative analysis and combined with the field production process, the better controlled cooling parameters are obtained. Based on the theoretical research, a set of experimental platform for bar penetrating water cooling is designed, and the simulation results are verified by field experiments. The main contents are as follows: firstly, the computational fluid model of cooling tube and bar is established. The fluid flow state and the temperature change of the bar during the process of water cooling are studied by means of the fluid simulation software FLUENT,. The simulation results show that when the fluid passes through the cooling tube's contraction and expansion zone, turbulence will occur due to the difference in velocity, and the local turbulence will break the steam film produced by the cooling water and bar, so that the surface of the rod is in full contact with the cooling water. Improve cooling effect. At the same time, the analysis of the bar temperature field shows that the surface temperature of the bar will drop sharply during the impact of cooling water, and when the bar temperature drops to a certain temperature, the bar temperature will tend to a certain value. Secondly, under the condition of changing water pressure and water entry angle, the temperature change during bar cooling is simulated. At the same time, the water pressure has a great influence on the temperature drop of the bar, but the influence of the angle is small, but if the angle is too high, there will be some obstacles to the cooling of the bar. Through the data obtained by simulation, the suitable water pressure and angle are selected, which lays the foundation for the establishment of the experimental platform of bar penetrating water cooling below. Then, the experimental platform including heating, conveying and cooling bar is designed. The heating frequency, power supply and coil turns of the electromagnetic induction heater are determined, and the conveying roller table and its motor are calculated and selected. At last, the field experiment of bar penetrating water cooling proves that the simulation results of bar cross water cooling have high reliability.
【学位授予单位】：安徽工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG335.62

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