• CN:11-2187/TH
  • ISSN:0577-6686

›› 2014, Vol. 50 ›› Issue (12): 51-57.

• 论文 • 上一篇    下一篇

Inconel690合金圆管挤压变形行为无网格法研究

张勃洋;张清东;毛艺伦;张晓峰   

  1. 北京科技大学机械工程学院
  • 发布日期:2014-06-20

Research on Inconel690 Tube Extrusion Forming By Element-free Method

ZHANG Boyang;ZHANG Qingdong;MAO Yilun;ZHANG Xiaofeng   

  1. School of Mechanical Engineering, University of Science and Technology Beijing
  • Published:2014-06-20

摘要: 针对Inconel690镍基高温合金圆管挤压变形过程,推导建立圆柱坐标系下无网格伽辽金(Element-free Galerkin, EFG)法的求解模型并编制软件程序,采用Gleeble-1500热模拟机试验建立Inconel690的本构模型,实现了对于Inconel690镍基高温合金圆管挤压变形行为的数值模拟。所开发的EFG方法,采用罚函数法施加本质边界条件,利用反正切摩擦模型计算边界摩擦力,应用Newton-Raphson迭代方法求解刚度方程。为了验证所建EFG方法及软件,通过多次随机选取变形区内若干节点,提取其速度场、等效应变速率和等效应力的计算值,并与相同工况下的DEFORM有限元计算结果进行对比,最大的相对差不大于8%;将仿真计算得到的稳态挤压力与某工厂同样工况条件下的挤压力实测值相比较,最大的相对差小于7%。运用所建立的EFG方法求解模型和软件,仿真研究Inconel690高温合金圆管挤压过程,求得稳态挤压力、速度场、等效应变速率场以及等效应力场,分析获得塑性变形区内金属变形规律;并以某工厂的挤压机为对象,以挤压力最小为优化目标,借助正交试验法设计模拟计算工况,得到了较优的挤压工艺参数。

关键词: Inconel690合金;挤压;无网格伽辽金法;工艺优化

Abstract: According to the problem of large extrusion deformation of Inconel690 nickel-based superalloy, the solving process of element-free Galerkin method(EFG) in cylindrical coordinates and the software program is prepared, the Inconel690 alloy flow stress constitutive relation model is established with adopting Gleeble-1500 thermal simulation experiment machine, and the Inconel690 nickel-base superalloy tube extrusion deformation behavior is also simulated. The EFG method is established with using penalty function imposed on essential boundary conditions, computing boundary friction with arctangent friction model adopted and solving stiffness equation using Newton-Raphson iterative method. Extrusion pressure compared with measured values error within 7%. In the deformation zone randomly selected several nodes, the results are compared with the DEFORM calculations, the maximum error is within 8%, the correctness of meshless EFG and the software is demonstrated. The calculated results show the steady extrusion pressure, velocity field, equivalent strain rate field and equivalent stress field. The plastic deformation zone deformation behavior of metals with the calculated results is analyzed. And based on the EFG method and the software established in this paper which improves optimize efficiency, the minimum extrusion pressure of nickel-based superalloy hot extrusion deformation process as the optimization goal, Inconel690 nickel-base superalloy tube hot extrusion process parameters with orthogonal experimental design simulation conditions is optimized.

Key words: Inconel690 alloy;extrusion;element-free Galerkin method;process optimization

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