AZ31镁合金薄板温轧过程的数值模拟研究

发布时间：2018-03-04 00:23

本文选题：AZ31镁合金　切入点：薄板　出处：《天津职业技术师范大学》2016年硕士论文　论文类型：学位论文

【摘要】：镁合金是目前工程应用中最轻的金属结构材料,具有较高的比强度及比刚度、良好的减震性及导热性、绝佳的电磁屏蔽性、易切削回收等优点,被誉为“21世纪最具发展前景的绿色工程材料”。镁合金板材特别是高性能镁合金薄板的发展前景尤为广阔。但传统方法制备的镁合金薄板在质量和产量上均已经无法满足现代工业的需求,温轧作为一种新型的轧制工艺是目前优质变形镁合金薄板研发的重要方向之一。传统的实验手段费用高、周期长,因而本文基于有限元的方法研究镁合金薄板温轧过程的成形规律,为使用温轧工艺生产优质镁合金薄板提供理论指导。本文首先以AZ31镁合金薄板的温轧过程为研究对象,根据已有研究及实验数据,建立AZ31镁合金薄板单道次温轧模型,分析二维、三维模型下的温轧结果;其次,在单道次温轧的基础上,采用小压下量进行多道次温轧模拟,分析多道次小压下量温轧的成形规律;最后在不同工艺条件下进行温轧模拟,分析温轧工艺参数对轧制过程的影响。主要研究内容及其结果如下:在镁合金轧制成形理论及有限元相关机理的基础上,根据已有研究及实验数据确定了温轧模拟需要的材料性能参数及有限元计算条件,利用ABAQUS软件建立了单道次温轧模型,进行了二维、三维温轧模拟。结果表明:温轧后薄板的温度场在板厚方向均呈明显的阶梯分布,且二维与三维模拟结果基本一致,但二维模拟比三维模拟更加清晰、直观,且计算时间明显减少。在分析单道次温轧模拟的基础上进行了多道次温轧模拟。结果表明:多道次温轧时,薄板的温度场及应力应变场分布受上一轧制道次的影响,其温度分布梯度、等效应力应变分布梯度均小于单道次轧制。利用AZ31镁合金二维温轧模型,在不同工艺条件下进行了温轧过程的数值模拟。结果表明:在薄板温轧过程中,随压下量的减小,轧制速度的增大,轧件温度均升高;随轧制温度及轧制速度的升高,压下量的减小,等效应力值均减小;随压下量的减小,等效应变值减小;轧辊转速不变时,随轧制温度的上升、压下量的减小,轧制力减小,压下量不变时,随轧件温度及轧辊转速的上升,轧制力减小。
[Abstract]:Magnesium alloy is the lightest metal structure material in engineering application at present. It has the advantages of high specific strength and specific stiffness, good shock absorption and thermal conductivity, excellent electromagnetic shielding, easy cutting and recovery, etc. In 21th century, magnesium alloy sheet, especially high performance magnesium alloy sheet, is considered as "the most promising green engineering material". However, the quality and yield of magnesium alloy sheet made by traditional methods have been lost. To meet the needs of modern industry, As a new type of rolling technology, warm rolling is one of the important directions in the research and development of high quality wrought magnesium alloy sheet. Therefore, based on finite element method, the forming law of hot rolling process of magnesium alloy sheet is studied in this paper, which provides theoretical guidance for the production of high quality magnesium alloy sheet by warm rolling process. Firstly, the warm rolling process of AZ31 magnesium alloy sheet is taken as the research object. According to the existing research and experimental data, the single pass warm rolling model of AZ31 magnesium alloy sheet is established, and the results of warm rolling under two and three dimensional models are analyzed. Secondly, on the basis of single pass warm rolling, multi-pass warm rolling simulation is carried out with small reduction. The forming law of multi-pass small reduction warm rolling is analyzed, and the simulation of warm rolling under different technological conditions is carried out. The main research contents and results are as follows: based on the rolling forming theory of magnesium alloy and the relevant mechanism of finite element, According to the existing research and experimental data, the material performance parameters and finite element calculation conditions for warm rolling simulation are determined. The single-pass warm rolling model is established by using ABAQUS software, and the two-dimensional model is carried out. The results show that the temperature field of the sheet after warm rolling has obvious ladder distribution in the thickness direction, and the results of two-dimensional and three-dimensional simulation are basically the same, but the two-dimensional simulation is more clear and intuitive than the three-dimensional simulation. Based on the analysis of single-pass warm rolling simulation, the multi-pass warm rolling simulation is carried out. The results show that the distribution of temperature field and stress-strain field of thin plate is influenced by the previous rolling pass. The temperature distribution gradient and equivalent stress strain distribution gradient are all smaller than single pass rolling. The numerical simulation of warm rolling process of AZ31 magnesium alloy is carried out under different process conditions by using two-dimensional warm rolling model of AZ31 magnesium alloy. The results show that: in the process of warm rolling of thin plate, With the decrease of rolling temperature and rolling speed, the rolling temperature increases, with the decrease of rolling temperature and speed, the equal effect force decreases with the decrease of rolling temperature and speed, and the equivalent strain value decreases with the decrease of rolling speed. With the increase of rolling temperature and rolling speed, the rolling force decreases and the rolling force decreases with the increase of rolling temperature and roll speed.
【学位授予单位】：天津职业技术师范大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TG339

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