共查询到17条相似文献,搜索用时 203 毫秒
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三辊行星旋轧变形复杂剧烈,对于其成形规律的研究具有很大的难度.本文采用有限元技术分析了三辊行星旋轧过程中变形规律,讨论了有限元模拟的关键技术.研究表明:三辊行星旋轧过程中,坯料的运动轨迹呈螺旋形,管坯的变形是通过一系列连续的局部小变形累积成整体的大变形.管坯在旋轧过程中要经受一个由圆形、三角形、再归整到圆形的变形过程. 相似文献
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三辊行星轧制过程中摩擦状况较为复杂,其对轧制过程的影响也较为复杂.采用有限元软件ABAQUS建立了具有轧辊公转的铜管三辊行星轧制过程的三维热力耦合有限元模型,在该仿真模型中,根据轧辊各段的摩擦状况,将轧辊分成3个区域,分别研究了各变形区域内摩擦系数对行星轧制过程中轧制速度和扭转情况的影响.研究结果表明:随着区域1以及区域2处摩擦系数的增大,轧件出口轴向速度和轧件出入口角速度差均有所增加,区域3处摩擦系数的影响规律则与之相反;适当增大区域1和区域3处的摩擦系数,可以减小轧制过程中的扭转,而区域2处的摩擦状况对轧制扭转的影响较小. 相似文献
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行星轧机的运动形式和轧管组织变化 总被引:7,自引:1,他引:7
文章结合三辊行星轧机的结构描述和工作原理,分析了轧制过程中轧管运动形式和轧制过程中轧管不旋转的条件。同时对变形区中的坯料的组织变化规律进行分析,阐明了各部分组织的变化。 相似文献
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文章借助大型非线性有限元分析软件MSC.Marc,建立了铜管四辊行星轧制三维弹塑性有限元模型,并对四辊行星轧制过程进行了热-力耦合分析。获得了四辊行星轧制过程中铜管横断面的变形过程以及管坯温度场分布,并对轧制过程中轧辊受力进行了分析。将模拟结果与实验进行对比,认为该有限元模型可靠,且具有一定的精度,可用于铜管四辊行星轧制工艺参数的优化,并对模具设计具有一定指导意义。 相似文献
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利用有限元分析软件ANSYS/LS-DYNA,对三辊行星轧机轧制过程进行了有限元分析.介绍了有限元模型的建立、约束的定义和载荷的施加.根据模拟仿真结果,对轧件的应力和应变分布、轧制负荷以及轧件速度进行了分析. 相似文献
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Bing Li Shi Hong Zhang Hai Qu Zhang Guang Liang Zhang 《Journal of Materials Engineering and Performance》2008,17(4):499-505
During three-roll planetary rolling, the microstructure of copper tube with initial columnar grains develops into an equiaxed
grain structure due to the large rolling deformation and high rolling temperature. The microstructure of copper tubes significantly
influences formability and properties due to the three-roll planetary rolling operation. It is very important to understand
the microstructural evolution for such special processing. It was found that dynamic recrystallization occurred at the concentrating
deformation zone, followed by rapid grain expansion that gradually stabilized. Corresponding with the transformation of microstructure,
the hardness of the tube billet reduced gradually away from the roller’s concentrating deformation zone. The changing of roller
velocity is responsible for the extreme evolution of the microstructure in the concentrating deformation zone. Therefore,
the properties of copper tubes can be controlled by concentrating the deformation zone. This research can facilitate the application
of planetary rolling to the manufacture of tubes for low formability materials. 相似文献
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J.H. Min H.C. Kwon Y. Lee J.S. Woo Y.T. Im 《Journal of Materials Processing Technology》2003,140(1-3):471-477
In process design of bar rolling, accurate prediction of deformed shape of the rolled workpiece is important in determining the total number of passes. Thus, development of an approximate analytical model for predicting an accurate rolled shape with less computation time will be beneficial for practical purpose. In the present study, such a model for the three-roll system with multi-passes was developed by deriving spread and geometrical configuration formulae from the finite element (FE) analysis results of a seven-passes sequence rolling. In FE simulations, process parameters such as the initial workpiece geometry and the amount of roll draft and roll speed were varied. By comparing spread ratios of FE simulation results three representative geometry changes (round–curved hexagonal, curved hexagonal–hexagonal, and hexagonal–hexagonal) were identified. For each representative geometry change those two formulae were determined in the present investigation. The formulae determined were further applied to a three-roll process with four-passes sequence. The final workpiece geometry predicted based on the model developed was found to be in good agreement with experimental and FE simulation results. Thus, the analytical model developed in the current approach can be effectively used in the design of multi-pass three-roll rolling processes. 相似文献
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三辊行星轧制过程中ACR紫铜管的组织和性能演变 总被引:4,自引:0,他引:4
采用金相显微镜、布氏硬度仪以及激光热导仪对三辊行星轧制过程中紫铜管的组织和性能进行研究。结果表明:在三辊行星轧制过程中,先后存在着加工硬化和动态再结晶软化两个过程,急剧大变形使粗大的铜晶粒破碎、滑移并产生大量热量,致使变形区温度急剧上升,最终获得了动态再结晶组织;与组织转变相对应,硬度值表现为随变形量的增大而增加,因加工硬化和动态再结晶的共同作用保持稳定,再结晶完成时硬度值下降;由于空洞等缺陷在变形过程中被抵消,材料的热导率增大,再结晶开始后,晶粒变得细小,热导率下降。 相似文献
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三辊轧管的几个工艺问题 总被引:1,自引:0,他引:1
对三辊轧管的有关工艺问题进行了介绍。文章认为:正确选择产品品种和规格能充分发挥三辊轧管的特长;三辊轧管与三辊穿孔相匹配,可避免三辊轧管工艺自身造成的内折等表面缺陷,但不能避免管坯质量不良而造成的缺陷;采用三转角轧制法轧制厚壁管和相反的操作法轧制薄壁管可消除喇叭口与尾三角。 相似文献
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介绍了自曼内斯曼兄弟发明斜轧穿孔工艺以来,连续轧管、三辊轧管、MPM轧管、行星轧管工艺相继发明并投入生产的简要情况。近些年,CPS轧管工艺在南非已进行试验;第1台PQF轧管机组已在中国天津投产;行星阿塞尔(PAM)的设想已有雏形。简述PQF、CPS和PAM这3项轧管新工艺的特点,分别对其“新”的程度进行了比较和评价。指出PAM工艺将有可能从设想变成现实,并预测未来钢管生产领域还会有重大发明。 相似文献
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为了保证三辊连轧过程中棒材的成型精度,研究了TC4钛合金棒材的宽展。采用正交试验优化设计方法设计数值模拟方案,在Marc有限元平台上,研究轧制工艺参数(轧制温度、轧制速度、孔型内切圆直径、轧辊直径、摩擦系数)对宽展的影响,并分析了各参数的影响显著性顺序。在此基础上,建立了三辊轧制TC4棒材的宽展模型。试验在自行研制的8机架Y型连轧机上进行,孔型系统为平三角-圆。宽展测量结果和模型计算结果吻合较好。 相似文献