在冷拔薄壁管的生产过程中，有时会遇到拉链缺陷。生产经验表明，通过改变润滑条件和拉拔速度，可以减少这些缺陷的发生。本文采用二维有限元软件DEFORM对小直径铜管的多道次拉深成形进行了模拟。研究了退火、润滑、拉伸速度、模具设计和孔型顺序等各种工艺条件对管材主应力、损伤因子和最高温度的影响。研究发现，退火、模具设计和孔型顺序设计可以降低管材应力，从而消除拉链缺陷。

Zipper defects are sometimes encountered during the production of thin walled tubes by the cold drawing process. Production experience suggests that occurrence by these defects can be reduced by changing lubrication conditions and drawing velocity. In this paper, a 2-D finite element package DEFORM was used to model the multi-pass drawing of small diameter copper tubes. The effect of various processing conditions such as the effect of annealing, lubrication, drawing speed, die design and pass sequence on the principal stresses, damage factors and maximum temperatures in the tube were investigated. It is found that annealing, die design and pass sequence design can be used to reduce the tube stresses and thus eliminate the zipper defect.