棒材同轴复合时芯材与加工工具不接触，其横截面形状及尺寸精度控制难度大，采用方-椭圆孔型轧制时芯材圆度严重超公差。在建立覆材和芯材变形抗力模型的基础上，利用三维弹塑性热力耦合有限元方法对同轴复合棒材热轧变形过程进行数值模拟。分析了轧制孔型、覆材及芯材外形对轧制后芯材变形和形状的影响，用工业试验对模拟计算结果进行验证。结果表明：轧辊孔型设计对芯材不圆度的影响最明显，覆材及芯材外形是次要影响因素。这是因为方-椭圆孔型系统会导致最终轧件在横截面上的非对称等效累积应变分布，以及导致轧后芯材严重不圆。减少K4孔的轧件压下量，增加K3孔轧件压下量，可以改善方-椭圆孔型中轧件变形的对称性，减少芯材不圆度。
The cross-section profile and dimensional accuracy of core rod was hard to control because of no direct contact between the core rod and the forming tools while coaxial composite bar was rolled.The core rod roundness severely deviated from tolerance limits after hot rolled in square-oval grooves.Based on establishment of the de-formation resistance models of the clad and core materials,the deformation of coaxial composite bar in hot rolling process was numerically simulated by three dimensional thermal-mechanical coupled elastic-plastic finite element method.The effects of rolling pass design,clad and core contour on deformation and shape of the core material af-ter rolling were studied respectively.The numerical calculation results were verified by industrial rolling experi-ments.The results show that the influence of rolling groove design on the core ellipticity is remarkable,but the clad and core contours are the secondary factors.It is because that square-oval groove system leads to an asymmet-rical accumulative equivalent strain distribution on the cross section of the workpiece and the severe elliptic core af-ter rolling.Deceasing reduction of K4 groove and increasing reduction of K3 groove can improve the core symmetry deformation of the workpiece and reduce its out-of-roundness.
参考文献
| [1] | Zhongchun Chen;Keisuke Ikeda;Tadasu Murakami.Fabrication of composite pipes by multi-billet extrusion technique[J].Journal of Materials Processing Technology,20031/3(1/3):10-16. |
| [2] | 沈健;谢建新;谢水生.铝/铜合金复合材料的多坯料挤压成形[J].机械工程学报,1999(4):107. |
| [3] | 杨扬;陈忠平;李大河;刘晓辉.Monel合金/Cu爆炸复合棒界面的微观组织和力学性能[J].焊接学报,2008(8):53-56. |
| [4] | M. S. Mohebbi;A. Akbarzadeh.A novel spin-bonding process for manufacturing multilayered clad tubes[J].Journal of Materials Processing Technology,20103(3):510-517. |
| [5] | H. Hokari;T. Sato.Magnetic impulse welding of aluminium tube and copper tube with various core materials[J].Welding International,19988(8):619-626. |
| [6] | 罗奕兵;刘新华;谢建新.铜包铝复合棒材平辊轧制宽展变形行为[J].中国有色金属学报,2009(11):1976-1981. |
| [7] | 程满;洪慧平;彭聃;康永林;金永春.20MnSi钢筋热连轧及轧后分级控冷过程温度变化模拟[J].钢铁研究学报,2008(3):18-22. |
| [8] | 邢磊;张立文;张兴致.温度与载荷对GH4169/5CrMnMo界面接触换热的影响[J].中南大学学报（自然科学版）,2009(6):1568-1572. |
| [9] | 许小林 .中空钢轧制过程数值模拟及尺寸精度分析[D].燕山大学,2010. |
| [10] | F. Z. Wang;H. C. Zhang;X. Z. An;G. Q. Liu;L. Lu;G. Y. Zhu.Three-dimensional thermomechanical coupled FEM analysis of static recrystallisation during two-pass tube tension reducing process[J].Materials Science and Technology: MST: A publication of the Institute of Metals,20108(8):988-995. |
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