基于晶体塑性理论的板带材粗糙度研究

发布时间：2018-06-08 01:42

本文选题：晶体塑性 + 粗糙度　；参考：《燕山大学》2016年硕士论文

【摘要】：随着汽车板、镀锌板、家电板等高附加值产品日益广泛的应用,冷轧带钢表面质量越来越受到企业及学者的重视。现有关于冷轧带钢表面粗糙度的研究主要集中在对生产现场进行数据采集,对所得数据进行回归得出带钢表面粗糙度与工艺参数之间的关系,该方法所建模型并不具有普适性且不涉及粗糙度变化的根本。为了满足使用者对带钢的不同的使用要求,更加深入地研究冷轧过程中带钢表面粗糙度转印及变化的实质,本文在现有研究的基础上,对带钢表面粗糙度与晶粒关系进行了探讨,采用晶体塑性理论研究冷轧带钢表面粗糙度。本文通过建立Voronoi多晶模型,将晶体塑性本构引入到ABAQUS中模拟了冷轧过程中粗糙度的转印及变化,分析了工艺参数对轧制过程中粗糙度变化及转印率的影响规律。本文的主要研究内容包括:(1)分析比较了现有的建立多晶模型的方法,其中,基于Voronoi图的形成过程类似晶粒的形核与长大过程,能更真实地反映晶粒的外形及内部形状,因此利用Voronoi多面体建立了多晶模型;(2)研究晶体塑性本构理论,结合研究对象,在确定滑移系参数、硬化法则、弹性参数、增量算法及迭代算法的基础上,编写ABAQUS用户子程序,采用晶体塑性本构关系模拟带钢表层变形情况;(3)对比经典弹塑性本构关系和晶体塑性本构关系下的模拟结果,发现基于位错滑移机制的晶体塑性本构变形存在粘塑性拖-拽现象,使得轧辊粗糙凸峰与其在带钢表面留下的凹坑不完全贴合;(4)模拟了单粗糙峰下的转印过程,重点研究了压下量及轧制速度对粗糙度转印的影响,并分析了带钢晶粒大小对轧后表面粗糙度的影响;建立了轧制模型,研究了压下量和轧制速度对粗糙度变化的影响。
[Abstract]:With the increasing application of high value-added products such as automobile sheet, galvanized plate and home appliance plate, the surface quality of cold-rolled strip has been paid more and more attention by enterprises and scholars. The existing research on surface roughness of cold-rolled strip is mainly focused on collecting data from the production site and regressing the data to obtain the relationship between the surface roughness and technological parameters. The model established by this method is not universal and does not involve the fundamental change of roughness. In order to meet the different requirements of the users and to study the essence of surface roughness transfer and change in cold rolling process, this paper is based on the existing research. The relationship between surface roughness and grain size of cold rolled strip was discussed. The surface roughness of cold rolled strip was studied by crystal plasticity theory. In this paper, the Voronoi polycrystalline model is established, and the crystal plastic constitutive model is introduced into Abaqus to simulate the transfer and change of roughness during cold rolling. The influence of process parameters on the change of roughness and transfer rate during rolling is analyzed. The main research contents of this paper are as follows: (1) the existing methods of establishing polycrystalline model are analyzed and compared. The formation process based on Voronoi diagram is similar to the nucleation and growth process of grain, which can more truly reflect the shape and internal shape of grain. Therefore, a polycrystalline model based on Voronoi polyhedron is established to study the constitutive theory of crystal plasticity. Based on the determination of slip system parameters, hardening rules, elastic parameters, incremental algorithms and iterative algorithms, Abaqus user subprograms are compiled. The constitutive relation of crystal plasticity is used to simulate the deformation of steel strip surface layer, and the results are compared with those under the classical elastoplastic constitutive relation and the constitutive relation of crystal plasticity. It is found that there is a viscoplastic tow-pull phenomenon in the crystal plastic constitutive deformation based on the dislocation slip mechanism, which makes the rough convex peak of the roll and the pit left on the surface of the strip not fit completely.) the transfer process under the single rough peak is simulated. The influence of rolling speed and reduction on roughness transfer was studied, and the effect of grain size on surface roughness after rolling was analyzed, and the rolling model was established, and the influence of rolling speed and reduction on roughness was studied.
【学位授予单位】：燕山大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TG335.5

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