工艺参数对大规格钛扁锭凝固中的熔池形貌和非稳态过渡区长度的影响
发布时间：2018-07-17 22:00
【摘要】：钛的优异性能给很多行业带来了崭新的发展前景,钛材被大量运用在航天航空、国防工业等行业中。因此,国家正在重点发展钛产业,提升钛材的生产能力和加工能力。利用电子束冷床熔炼炉生产大规格钛扁锭是当今社会生产钛材的主要生产方式。为了得到优质的大规格钛扁锭,深入了解钛扁锭凝固过程的规律十分重要。本文主要研究大规格钛扁锭半连铸凝固过程中,温度场的分布以及温度场和应力场的耦合行为。大规格钛扁锭的生产过程中,不同的工艺生产条件对其凝固过程的影响较为明显,本文增加利用有限元软件ProCAST对大规格钛扁锭进行温度场的稳态数值模拟计算、温度场非稳态数值模拟计算以及应力场的数值模拟计算,分析不同工艺生产条件下,温度场和应力场的变化规律。在半连铸过程中,钛扁锭的固液界面形貌对其组织的形成有着重要影响。本文首先采用稳态数值模拟的方法,重点研究了浇注温度和拉锭速度对钛扁锭凝固过程的固液界面的影响规律。对钛扁锭进行温度场稳态模拟计算后,获得了浇注温度和拉锭速度对钛扁锭凝固达到稳态时凝固界面形貌和固相分数的影响机制。大规格钛扁锭的半连铸过程中,熔池形貌和过渡区长度对钛锭组织的形成有着重要的影响。本文采用非稳态数值模拟的方法,重点研究浇注温度和拉锭速度对大规格钛扁锭熔池形貌和过渡区长度的影响规律。研究表明,随着浇注温度和拉锭速度的增加,过渡区长度呈线性增加,固相分数和熔池形貌变化区域的长度呈线性减小。钛锭熔池深度和钛锭1/4处熔池的深度呈线性增加。相对于浇注温度,拉锭速度对非稳态过渡区和固相分数的影响更为显著。大规格钛扁锭的半连铸过程中,应力场的分布规律对钛锭质量有着重要的影响。经研究表明：钛锭在冷却凝固初期,表面应力大,随着冷却凝固时间的增加,内部的应力明显增加；钛锭的两侧和锭头部位应力较大,随着冷却凝固时间的增加,钛锭两侧的有效应力逐渐增大,最后逐步趋于平缓。钛锭两侧与锭头发生了形变,并且钛锭两侧形变明显。
[Abstract]:The excellent performance of titanium has brought new development prospects for many industries. Titanium materials are widely used in aerospace, national defense industry and other industries. Therefore, the state is developing the titanium industry, improving the production capacity and processing capacity of titanium. The production of large titanium flat ingot by using electron beam cold bed smelting furnace is the main part of the production of titanium materials in the society. In order to obtain high quality and large scale titanium flat ingot, it is very important to understand the law of solidification process of titanium flat ingot. In this paper, the distribution of temperature field and coupling behavior of temperature field and stress field in the solidification process of large titanium flat ingot in half continuous casting are mainly studied. In the production process of large flat titanium ingot, different process conditions are made. The influence of the solidification process is more obvious. In this paper, the finite element software ProCAST is used to calculate the steady state numerical simulation of the temperature field of the large flat titanium ingot, the unsteady numerical simulation calculation of the temperature field and the numerical simulation of the stress field, and the variation of the temperature field and stress field under different production conditions. In the process of casting, the solid-liquid interface morphology of the flat titanium ingot has an important influence on the formation of its microstructure. Firstly, the influence of the pouring temperature and the ingot velocity on the solid liquid interface of the flat ingot in the titanium flat ingot is studied by the steady state numerical simulation. In the semi continuous casting process of large flat titanium ingot, the morphology of the molten pool and the length of the transition zone have an important influence on the formation of the titanium ingot. The study shows that the length of the transition zone increases linearly with the increase of pouring temperature and the speed of the ingot, and the length of the region of the change of the solid fraction and the morphology of the molten pool decreases linearly. The depth of the molten pool and the depth of the molten pool at the 1/4 ingot at the titanium ingot are linearly increased. In the semi continuous casting process of large scale titanium flat ingot, the distribution of stress field has an important influence on the quality of titanium ingot during the semi continuous casting process of large flat titanium ingot. The stress on both sides and ingot head parts of the titanium ingot is greater. With the increase of cooling and solidification time, the effective stress on both sides of the titanium ingot increases gradually, and finally tends to be gentle. The deformation of the two sides of the ingot and the head of the ingot has been deformed, and the deformation of the two sides of the titanium ingot is obvious.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TG292
，
本文编号：2131060
[Abstract]:The excellent performance of titanium has brought new development prospects for many industries. Titanium materials are widely used in aerospace, national defense industry and other industries. Therefore, the state is developing the titanium industry, improving the production capacity and processing capacity of titanium. The production of large titanium flat ingot by using electron beam cold bed smelting furnace is the main part of the production of titanium materials in the society. In order to obtain high quality and large scale titanium flat ingot, it is very important to understand the law of solidification process of titanium flat ingot. In this paper, the distribution of temperature field and coupling behavior of temperature field and stress field in the solidification process of large titanium flat ingot in half continuous casting are mainly studied. In the production process of large flat titanium ingot, different process conditions are made. The influence of the solidification process is more obvious. In this paper, the finite element software ProCAST is used to calculate the steady state numerical simulation of the temperature field of the large flat titanium ingot, the unsteady numerical simulation calculation of the temperature field and the numerical simulation of the stress field, and the variation of the temperature field and stress field under different production conditions. In the process of casting, the solid-liquid interface morphology of the flat titanium ingot has an important influence on the formation of its microstructure. Firstly, the influence of the pouring temperature and the ingot velocity on the solid liquid interface of the flat ingot in the titanium flat ingot is studied by the steady state numerical simulation. In the semi continuous casting process of large flat titanium ingot, the morphology of the molten pool and the length of the transition zone have an important influence on the formation of the titanium ingot. The study shows that the length of the transition zone increases linearly with the increase of pouring temperature and the speed of the ingot, and the length of the region of the change of the solid fraction and the morphology of the molten pool decreases linearly. The depth of the molten pool and the depth of the molten pool at the 1/4 ingot at the titanium ingot are linearly increased. In the semi continuous casting process of large scale titanium flat ingot, the distribution of stress field has an important influence on the quality of titanium ingot during the semi continuous casting process of large flat titanium ingot. The stress on both sides and ingot head parts of the titanium ingot is greater. With the increase of cooling and solidification time, the effective stress on both sides of the titanium ingot increases gradually, and finally tends to be gentle. The deformation of the two sides of the ingot and the head of the ingot has been deformed, and the deformation of the two sides of the titanium ingot is obvious.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TG292
，
本文编号：2131060
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