镁合金双辊铸轧中铸轧辊的冷却研究

发布时间：2018-12-13 20:50

【摘要】：双辊铸轧技术是冶金及材料加工领域内的一项前沿技术。其工作原理为将熔融状态下的金属液体浇入两个反方向旋转的铸轧辊和侧封坝组成的熔池中,在极短的时间内,由于铸轧辊的冷却作用和轧制作用,熔融状态下的金属液体被铸轧成为厚度很小的金属薄带。因此在双辊铸轧技术中的热量输出的速率、铸轧过程中的热流密度、金属溶液的冷却速度、热流的峰值都比传统连铸连轧技术要高。所以双辊铸轧技术相比于传统连铸连轧技术有着速度快、流程短、能耗低、成本低等优点。并且由于铸轧冷却速度快可以起到使晶粒细化、偏析减少的目的,从而使铸带的质量能够得到改善。在该工艺中,铸轧辊同时起着结晶器和变形工具的作用,所以铸轧辊及时有效地冷却是整个铸轧过程顺利进行的关键所在。在镁合金双辊铸轧过程中铸轧辊是双辊式镁合金铸轧机最主要的工作关键部件,特别是镁这种金属易燃容易发生事故,因此在铸轧过程中冷却极其重要。而在整个过程镁合金双辊过程都是在冷却水的强烈冷却作用下进行的。所以研究冷却水温度及冷却水流速度对铸轧辊温度场的影响,可以进一步加深对铸轧工艺问题的认识。本文利用ANSYS有限元软件模拟在镁合金铸轧过程中铸轧辊在的温度场分布。通过分析其他条件一定的情况下,不同冷却水温度及冷却水速下铸轧辊轴向和周向温度场的分布情况,得出在镁合金铸轧过程中提高冷却水速可以降低铸轧辊的温度场,但随着冷却水速的提高这种能力逐渐减弱;而冷却水温度对铸轧辊温度场影响不大.并设计了一种提高铸轧辊的冷却能力的外冷系统,弥补了铸轧辊在镁合金快速铸轧中冷却能力不足的问题。为现场工作提供重要的参考依据。
[Abstract]:The technology of two-roll casting and rolling is one of the frontier technologies in metallurgy and material processing. The working principle is that the molten metal liquid is poured into the molten pool composed of two reverse rotating casting rolls and side sealing dams. In a very short period of time, due to the cooling and rolling action of the casting rolls, Molten metal liquid is cast into a thin strip of metal with a very small thickness. Therefore, the rate of heat output, the heat flux during casting and rolling, the cooling rate of metal solution and the peak value of heat flux in twin-roll casting and rolling technology are higher than those in traditional continuous casting and rolling technology. Compared with the traditional continuous casting and rolling technology, the double roll casting and rolling technology has the advantages of high speed, short flow, low energy consumption and low cost. Because of the fast cooling rate of casting rolling, the grain size can be refined and the segregation can be reduced, thus the quality of the cast strip can be improved. In this process, the casting roll plays the role of mould and deformation tool simultaneously, so the key point of the whole casting process is to cool the roll in time and effectively. In the process of magnesium alloy twin-roll casting is the most important part of twin-roll magnesium alloy casting mill. Especially magnesium metal is flammable and prone to accidents so cooling is extremely important in casting rolling process. In the whole process, the double-roll process of magnesium alloy is carried out under the strong cooling effect of cooling water. So the influence of cooling water temperature and cooling water flow velocity on the temperature field of casting roll can be further understood. In this paper, ANSYS finite element software is used to simulate the temperature distribution of casting roll in magnesium alloy casting process. By analyzing the distribution of axial and circumferential temperature field of casting roll under different cooling water temperature and cooling water speed under certain other conditions, it is concluded that increasing cooling water speed in casting process of magnesium alloy can reduce the temperature field of casting roll. However, with the increase of cooling water speed, the ability of cooling water becomes weaker. However, the cooling water temperature has little effect on the casting roll temperature field. An external cooling system was designed to improve the cooling capacity of casting roll, which made up for the insufficient cooling capacity of casting roll in magnesium alloy rapid casting rolling. To provide important reference basis for site work.
【学位授予单位】：太原科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG333.17

【参考文献】