镁合金带材铸轧过程的计算机模拟

【作者】 李斌；

【导师】 孙斌煜；

【作者基本信息】 太原科技大学 ， 钢铁冶金， 2014， 硕士

【摘要】 近几年来，随着人们对金属结构材料的要求和其他制造业的飞速发展，镁合金的需求越来越大。然而镁合金塑性变形较差，加工起来很困难，这就使得其产品的制造成本提高，不能扩大应用。因此能够低能耗、短流程、低成本的生产变形镁合金的技术受到人们的关注，双辊铸轧技术则符合这一要求。然而在双辊薄带铸轧过程中，工艺参数较多，若通过实验来验证并优化工艺参数，那将会浪费大量的时间、人力、财力。计算机模拟仿真技术的发展使得此问题得到了解决。本文结合山西省科技创新项目(镁合金带材铸轧技术及装备开发)，选取水平式双辊铸轧AZ31镁合金过程为研究对象，运用ANSYS Fluent软件对双辊薄带铸轧镁合金过程进行了数值模拟。根据双辊薄带铸轧镁合金工艺的特点，从广义流体角度，结合流固耦合理论，建立描述铸轧过程的湍流流动、传热的控制方程，对固相率，凝固潜热和粘度等问题进行了处理。采用二维有限元分析，结合正交分析方法讨论了铸轧工艺参数(浇铸温度、铸轧速度、轧辊辊缝、轧辊辊径、界面传热系数)对铸轧区温度场影响的显著性，得出影响显著性的工艺参数。采用三维有限元分析方法，建立了铸轧区、辊套、冷却水一体的三维模型，首先分析何种冷却水流动方式下对辊套的降温效果最好，然后在此冷却水流动方式下讨论浇铸温度、铸轧速度、冷却水流速对铸轧区温度场的影响，得出特定条件下的最佳工艺参数。更多还原

【Abstract】 In rencent years, as the demand of meatal structural materials and othermanufacture industry’s rapid development, the demand of magnesium alloy isincreasing. However, the poor deformation and difficult processing ofmagnesium make the manufacture cost high and application limited. Thereforethe low energy consumption, short process and low cost technology will bepaied more intention, which can be used to manufacture the wrought magnesium.Twin roller cast-rolling process is in accordance with the requirements. But thereare so many process parameters that if testing and optimizing them through theexperiment, it would waster much time, manpower and wealth during theprocess. The development of computer simulation technology makes theproblems solved. Combined with science and technology innovation project ofShanxi Province, which is magnesium alloy strip cast-rolling technology andequipment development, this paper selects horizontal double roller cast-rollingprocess of AZ31magnesium alloy as the research object and simulate it by usingANSYS Fluent software.According to the characters of this process, from the view of generalizedfluid and the fluid-structure interaction theory, this paper establishes the controlequation of turbulent flow with heat transfer during cast-rolling process, whichcan descripe roll casting, and solve some problems, such as the solid fraction,latent heat of solidification and viscosity.This paper discusses significance of the roll casting process parameters’influence on the temperature fileld in cast-rolling area, which are pouringtemperature, roll casting speed, roll gap, roll diameter and interface heat transfercoefficient, and draws the significant process parameter by usingtwo-dimensional finite element combined with orthogonal analysisi method.This paper uses a three dimensional finite element analytical method toestablish a model of cast-rolling area, roller sleeve and cooling water, analysiseswhich is the best cooling water flow model to cool roller shell and thendiscusses the pouring temperature, the cast-rolling speed, cooling water flow velocity on the influence of the temperature filed in cast-rolling area with thebest cooling water flow model.更多还原