【作者】 沙明红；

【导师】 郑贤淑；

【作者基本信息】 大连理工大学 ， 材料加工工程， 2005， 硕士

【摘要】 连续铸造在金属材料生产中占有举足轻重的地位,连铸技术的水平成为衡量钢铁工业现代化程度的重要标志。结晶器是连铸机的“心脏”,连铸技术的发展离不开结晶器技术的发展。铸件凝固过程数值模拟是计算机在铸造生产中应用的最核心内容,数值模拟技术代替部分传统的经验性实验工作,一方面提高生产效率、降低成本和能耗,另一方面减少环境污染,是适应可持续发展战略的研究方向。结晶器的传热和变形影响铸坯的表面及内部质量,而且其使用寿命直接影响铸坯的产量。因此,本文以连铸结晶器的温度场为中心,将实验与数值模拟相结合,展开了如下研究: 设计了模拟结晶器工作过程的动态及静态水流作用下结晶器内壁界面温度分布实验,得到了结晶器内壁边界温度分布规律。 建立了结晶器边界等效导热系数模型,使连续铸钢过程中,包括结晶器在内的连铸钢坯温度场的数值模拟能够进行。 进行了圆柱拉坯实验,选用低熔点的锡铅合金模拟钢熔体。铸坯直径30mm,拉坯速度3mm/s,冷却水流量O.08m~3/h。实验结果与数值模拟结果基本符合,验证了数值模拟软件的可行性。 为了系统研究铸件与铸型的边界传热,对普通铸件的凝固进行了测温实验。实验测得了砂型和会属型冷却条件下,相同材质铸件凝固过程中的边界温度分布及各自对应的凝固组织。 自行编写VC++计算程序,对连铸钢小方坯及其结晶器的温度场进行数值模拟,得到了温度场的分布规律。模拟计算了工艺参数对结晶器温度场的影响,在连铸过程中,拉坯速度、冷却水流量及结晶器壁厚是温度场的主要影响因素。液柱高度、浇注温度对温度场的影响程度较小。更多还原

【Abstract】 Continuous casting technique is very important in the production of metallic material. The level of continuous casting technique has been the standard of modernization degree of iron and steel industry. Mold is the heart of continuous casting machine. The continuous casting technique develops along with the development of mold technique. The numerical simulation of solidification process is the core of application of computer in cast production. Numerical simulation instead of part of the conventional experience experiments can not only increase product efficiency and decrease cost and energy sources, but also lessen environment pollution. The heat transfer and thermal distortion of mold affects the surface and inside quality of billets, and the employ life of mold has effect on billets yield. Hence the paper makes the mold temperature field to be the center and performs the following research integrating the simulation and experiments.Experiments of dynamic and static for mold working process were designed and performed, the measure results indicates that the boundary temperature of mold wall always approaches that of cooling-water under the cooperation of molten metal and cooling-water.The mathematical model of equivalent thermal conductivity coefficient was built, which made the numerical simulation of billet including mold possibly during the continuous casting of steel.The experiments of column continuous casting were performed. The metal is Sn-Pb Alloy, and column diameter is 30mm, and casting speed is 3mm/s, and cooling water flux is 0.08m3/h. The experiments results agree with the calculation, which validates the feasibility of numerical simulation software.In order to make the study of boundary heat-transfer for cast and mold completely, the paper pursued experiments for common cast. The experiments got the rules of temperature distribution and solidification structure under different cooling boundary of sand mold and metal mold.VC++ programs were written to calculate the temperature field of mold for billet continuous casting of steel. The calculations got the distribution rules of temperature field for mold, and the effects of techniques parameters on temperature field were also calculated. During the continuous casting process, casting speed, cooling-water flux and mold wall thickness are the main factors. And the effects of metal level and pouring temperature are not so clear.更多还原