圆柱体内部空洞的热锻闭合条件

Void closing conditions for solid cylinders during hot forging

为在锻造过程中消除锻件内部的空洞型缺陷,采用有限元数值模拟技术,研究了各种情况下圆柱体锻件的内部空洞的热锻闭合变形条件,分析了各种因素对空洞闭合的影响。研究结果表明,影响大锻件内部空洞闭合的主要因素是锻件的高径比、空洞形状和空洞位置。当锻件高度与直径接近相等时,心部空洞最容易闭合;当高度大于直径时,随着高度增加,心部空洞闭合难度增大;而当高度小于直径时,增大直径也导致空洞闭合难度稍有增加。空洞为椭球形时,纵横半径之比愈大则闭合愈难。空洞位于锻件心部时闭合最容易,其位置愈接近端面愈难于闭合。

The closing of voids in solid cylinders during hot forging was numerically simulated using the finite element method for various conditions. The deformation conditions necessary for void closing were investigated. The results showed that the main factors influencing the void closing are the ingot height to diameter ratio, the void shape and the void position. The voids are most easily closed if the ingot height is approximately equal to the diameter. The void closing becomes more diffcult as the ratio of height to diameter goes higher than one, and it becomes slightly more difficult too as the ratio goes lower than one. For oral voids the closing difficulty increases as the ratio of vertical radius to horizontal radius goes higher. Voids at the center of the ingots closed most easily, whereas voids near the contact surface were more difficult to close.