• CN:11-2187/TH
  • ISSN:0577-6686

›› 2006, Vol. 42 ›› Issue (8): 215-219.

• 论文 • 上一篇    下一篇

大型锻件内部空洞缺陷修复的力学条件

任运来;聂绍珉   

  1. 燕山大学机械工程学院
  • 发布日期:2006-08-15

HEALING MECHANICS CONDITION OF LARGE FORGINGS INTERNAL VOID DEFECT

REN Yunlai;NIE Shaomin   

  1. College of Mechanical Engineering, Yanshan University
  • Published:2006-08-15

摘要: 介绍了大型锻件内部缺陷修复条件研究的现状,针对钢锭内部空洞缺陷的尺寸远远小于本身尺寸的特点,依据圣维南原理,将各种空洞缺陷的形状假设为数学上可处理的椭球形。由于大型锻件的锻造是在高温下进行的,材料具有粘性流动的特征。在上述分析假设的基础上,对于线性粘性材料模型,利用损伤力学中远场应力与物体内部微观损伤的力学关系,得到了锻造过程中外载荷与内部空洞体积变化的解析式,进而得到了空洞缺陷闭合的修复条件。条件表明应力状态影响空洞的闭合方式,三向压应力是修复空洞缺陷的最佳应力状态。该条件可直接根据锻造水压机的在线载荷与压下量计算锻件内部空洞缺陷的修复情况。不同边界应力状态下的试验表明,计算结果与试验结果接近。

关键词: 材料加工, 大锻件, 锻造, 缺陷修复条件, 塑性变形

Abstract: The researching status on healing condition of internal defect of large forgings are introduced. To counter the characteristics that the size of voids are much less than that of ingots. According to St.venant‘s principle, the shape of voids is supposed to be ellipse shape which is dealt with easily in mathematics methods. Because the forge of large forges is done at high temperature, materials have character of viscosity flow. On the base of above-mentioned reasonable hypothesis, for linear viscous materials, the mechanics relation of fever stress and internal voids of object are made use of, which appears in the damage mechanics, the analytical equation which shows the relation of loads and void’s deformation is obtained, and then the healing mechanics condition of large forgings internal void defects is gotten. It indicates that stress state affects the close ways of voids and three-dimensional compressive stress state is the best one for healing the internal voids of object. This condition makes it possible straight to calculate deformation of voids by using the loads and reduction which are shown in hydraulic press, the healing condition of internal defect become more practicable. The discussions about different boundary stress and experiments show that the calculating results is agreeable with results of experiments.

Key words: Forge, Healing condition of defect, Large forgings, Material processing, Plastic deformation

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