Bahagian 1. Bagaimana Untuk Mengawal Ubah Bentuk tiub lancar ketepatan semasa proses lukisan sejuk

Kertas ini berkaitan dengan ubah bentuk tiub lancar ketepatan semasa proses lukisan sejuk,using Finite Element Methods。yang
通过立体学测量度晶界变形获得应变的值与每个的模拟结果进行了比较
drawing pass。选择的材料是E235和E355钢等级,which is drawn from the initial dimension of Φ70 x6.3mm to the final
dimension of Φ50 x 3.75MM乘两个传球。FEM Software DEFORM 2D with the Lagrangian method is used to numerical analyses of the cold
drawing process。

1 pengenalan
Cold drawing technology used for manufacturing of precision seamless tube depends on many factors。冷形成过程参数,tool geometry initial and final tube dimension are selected to ensure a high quality of the tubes。In order to achieve the final diameter and wall thickness,在几个冷绘图步骤中，试管均依次减少。
This can be done by either drawing the tube through a die and by adding a plug,which results in better defined wall thickness and inner surface quality。使用固定插头的冷绘图是一种多功能技术，通常在ŽeleziarnePodbrezováIronworks Company中使用。将该公司的实验结果与本文所述的数值模拟进行了比较。

2Experimental Material
Dalam kerja ini,steel grade E235 and E355(ferritic-pearlitic carbon steel,请参阅选项卡le was considered;as a feedstock for cold drawing,hot rolled tube with dimensions of70 x 6.3选择了MM。Mechanical properties of E235 steel are as follows:yield stress Re =（226 245）MPA，tensile strength Rm343 441) MPa,延性A524，Sifat Mekanikal Keluli E355 Adalah Seperti Berikut：yield stress Re =(335 355) MPa,tensile strength Rm490 630）MPA，延性A524

2.1工件和材料建模工具
随着温度在冷图中保持较低,材料特性不变，因此可以独立于温度变化。As the material behavior is considered temperature independent,权力定律本构方程
material plastic properties can be used eq。1。代表等效塑料应变的其中，有效的塑性应变速率,和材料参数是通过拉伸测试确定的[1, 5],they are listed in Table2。

The tube material was considered as plastic,the hardening is assumed as isotropic,并将产量功能类型设置为von mises。
管子的几何形状已被融合。The eight elements are across the wall of the tube in first pass the six are in second pass Fig。5。这种工件网格足以准确，并且在计算过程中不需要重新网格程序。
The forming tools（（（（（mandrel and die)被认为是刚体。The mesh of tools did not need to be generated for simulation。

2.2数值模拟
变形2D和Lagrangian计算已设置为冷图技术的数值模拟,according to the tool dimension given on Table3.The initial axisymmetric geometric configuration has been set。图速度是9实验图和模拟边界条件中所有通过的M.Min-1。The friction model between the tools and the material was chosen to be a shear-type with the value of0.08.

The data interpolation functionality was used to set the second pass calculation。The final data from first pass was transfer,and to set second pass。This data transformation must be done,because drawing technology were performed without an interoperative annealing。

2.3Tube Drawing Technology

The main production steps for tube cold drawing technology in Železiarne Podbrezová are
seperti berikut:
• feedstock pre-processing(热滚动管，尺寸为Ø70x6.3 mm).
•管子的冷/热点末端(目标直径40毫米）。
•管的化学处理(acar, phosphating,lubrication）。
•冷图(请参阅选项卡。3有关详细信息）。
• intermediate annealing and final annealing in protective atmosphere。
• final conditioning。
•表面检查, pembungkusan,rust-proofing。
• 派遣。
The final reduction of the tube area for two-pass technology(来自Ø70x6. 3mm to Ø50 x3.75毫米）Adalah 57.78％；该值在所有通过中都相当统一
(lihat Jadual 3).Calculation of tube cross-section(area)减少:

分析了试管的局部塑性变形。在随后的绘图步骤中,the tube undergoes plastic deformation。变形管的最终几何形状和特性取决于应变值。It is possible to investigate change of material structure and predict plastic deformation。
The microstructure of each pas was observed in orthogonal tangential and longitudinal plane of deformed tube with about 500x magnification of light microscope and metallographic cut Fig1。切向套管削减是三次。On the inside of the pipe surface “I”,在管墙无花果的管道表面“ O”和中间“ M”的外部。2。由于塑性变形,结构各向异性增加 - 谷物
观察到零件变形位置的边界方向。分析位置中的局部应变是通过立体测量晶界方向获得的[4，6]。各向异性微观结构使用定量金理分解为各向同性和面向平面的组件[3, 4] (Saltykov stereology methods with oriented test lines）。表中列出了变形区中局部塑性变形的测量和计算的参数4.