【作者】 侯晓东；

【导师】 谷万里； 朱光明；

【作者基本信息】 山东理工大学 ， 材料加工工程， 2010， 硕士

【摘要】 双辊薄带铸轧工艺因其具有众多优点而受世界广泛关注,研究双辊铸轧熔池内钢液的流动、传热、凝固状况对双辊薄带连铸布流系统的设计以及连铸工艺参数的优化都有着非常重要的理论价值与实际意义。本文以某钢铁公司的双辊薄带铸机为原型,采用楔形布流器,以旋转的结晶辊、侧封板以及布流器围城的熔池区域作为研究对象,考虑铸辊的转动对熔池流场和温度场的影响,把整个铸轧熔池看作空气和钢水的两相自由表面流动,建立了钢水流动传热凝固的数学模型,并分析了布流器的结构和铸轧工艺参数对钢水的流动形式、熔池自由液面温度以及铸坯出口温度分布的影响。研究表明采用楔形布流器时,双辊铸轧熔池内钢液温度在纵向对称面上根据布流器侧水口的位置近似呈正弦形式分布,并且在侧封板附近,液面温度较高,而出口温度较低；当布流器侧水口倾角在0°到33°之间选取时,铸带宽度方向的温差相对较小,温度分布比较均匀；随着水口高度的提高熔池液面温度增加,同时铸坯出口温度降低；随着拉坯速度的提高熔池自由表面和出口的温度均提高；随着钢水过热度的提高熔池液面温度和铸坯出口温度都有所提高。在实际的铸轧过程中,可利用本文研究结果,通过合理控制铸轧工艺参数来控制钢液的凝固速度和避免液面结壳,以最大化的减少铸带缺陷,提高薄带质量,同时,本文为合理的设计双辊薄带铸轧布流系统提供了重要的理论依据。更多还原

【Abstract】 As an international frontier technology, the twin-roll strip casting process has a very large potential power in market competition. But so far, most of the thin strips produced by this casting process have a variety of defects. The structure of flow distribution device and the process parameters determine the flow and thermal conduction pattern in the molten pool. The study on flow and thermal conduction of molten steel in twin-roll pool has a very important theoretical and practical significance.This paper takes the molten pool as research object constructed by twin-roll, side dam and wedge-shaped device. Taking roll rotation into consideration, the mathematical model of flow and solidification is established with the entire casting pool as a two-phase free surface flow of air and molten. In this case, the effects of the structure of wedge-shaped device and casting process parameters on molten steel flow pattern, temperature ditribution on pool surface and the slab temperature distribution are analyzed.The research results show that the temperature of molten steel in the longitudinal symmetry plane distributes in the approximation cosine pattern bsed on the inlet location. When the nozzle angle is between 0°and 33°, the temperature difference is relatively small in the longitudinal direction of casting strip, so, the temperature distribution is relatively even. The surface temperature of molten pool increases with increasing of nozzle height, while the slab temperature is reduced. In addition, the temperature of free surface and outlets are both increased with the increasing of casting speed pool and superheat temperature. In the actual casting process, the solidification rate of molten steel will be controlled and level surface crusts will be avoided by the rational operating of casting process parameters according to the results. So, the casting defects will be reduced largely. Meanwhile, the results provide a theoretical basis for designing a reasonable flow distribution system in two-roll strip casting.更多还原