TWIP钢异步热轧变形区应变场的有限元分析

发布时间：2018-06-22 16:31

本文选题：TWIP钢 + 异步热轧　；参考：《安徽工业大学》2017年硕士论文

【摘要】：TWIP(Twinning Induced Plasticity)钢又称孪晶诱发塑性钢,它的组织性能与其轧制后退火过程产生的细小孪晶组织密切相关,与同步热轧相比较异步热轧退火板带在变形区更易于轧制变形渗透,可获得更加细小的孪晶组织,以及更高的γ织构组分,这是由异步轧制在变形区内可获得更大的等效应变和剪切形变引起的。但是,异步热轧过程变形区垂直断面厚度方向存在微观组织梯度(即变形区上下表面比心部晶粒更加细小),工艺对变形区厚度方向应变场的影响,及其在厚度方向应变场的差异性还缺乏系统深入的研究。本文采用刚塑性有限元法对TWIP钢异步热轧过程进行数值仿真,分析异速比、初始温度、压下率、工作辊辊径、摩擦系数等工艺参数对板带心部形变和厚度方向应变场差异性的影响,构建相关数学模型。具体研究内容如下:(1)通过热物性参数实验和圆柱体单轴压缩实验,测定材料的热物性参数和真实应力-应变曲线,采用MATLAB软件回归材料的变形抗力模型。(2)采用二维刚塑性有限元法建立用于异步热轧过程变形区应变场分析的数值仿真分析模型,通过心部剪切形变随单元数量变化的规律性研究来确定最佳的网格划分方式,通过最大轧制力计算值与实测值的比较来验证有限元模型的有效性。(3)基于数值仿真结果,研究不同工艺参数对板带心部应变(剪切应变ε12、压应变ε22、等效应变εe)和板带垂直断面厚度方向应变差异性的影响,并构建相关数学模型。
[Abstract]:TWIP (Twinning induced plasticity) steel is also known as twin-induced plastic steel. Its microstructure and properties are closely related to the fine twinning microstructure produced by the annealing process after rolling. Smaller twin structures and higher 纬 -texture components can be obtained due to the larger equivalent strain and shear deformation obtained by asynchronous rolling in the deformation region. However, the microstructure gradient exists in the vertical section thickness direction of the deformation zone during asynchronous hot rolling (that is, the upper and lower surface of the deformation zone is smaller than the grain in the center), and the effect of the process on the strain field in the thickness direction of the deformation zone is obtained. The difference of strain field in thickness direction is still lack of systematic and deep research. In this paper, rigid plastic finite element method is used to simulate the asynchronous hot rolling process of TWIP steel. The ratio of different speed, the initial temperature, the reduction rate and the diameter of work roll are analyzed. The influence of the friction coefficient and other technological parameters on the deformation and thickness direction strain field difference of the plate and strip is studied, and the related mathematical model is established. The specific research contents are as follows: (1) the thermal physical parameters and the true stress-strain curves of the materials are measured by the experiments of thermal physical parameters and uniaxial compression of cylinders. MATLAB software is used to regress the deformation resistance model of materials. (2) Two-dimensional rigid-plastic finite element method is used to establish a numerical simulation analysis model for strain field analysis in the deformation zone of asynchronous hot rolling. The best meshing method is determined by studying the regularity of shear deformation of the core with the number of elements. The validity of the finite element model is verified by comparing the maximum rolling force calculation value with the measured value. (3) based on the numerical simulation results, the finite element model is validated. The effects of different process parameters on the strain difference in the central part of plate and strip (shear strain 蔚 12, compressive strain 蔚 22, equivalent strain 蔚 e) and vertical section thickness of plate and strip were studied, and the related mathematical models were established.
【学位授予单位】：安徽工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG335.11

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