圆柱体内部空洞热锻闭合过程的数值模拟

通过合理制定热锻工艺来消除材料内部缺陷是材料加工领域的重要课题。本文应用商用有限元软件MARC ,模拟了圆柱体热镦粗时内部空洞的闭合过程 ,分析了空洞变形时的应力和应变以及影响空洞闭合和焊合的各种因素。模拟结果表明 ,变形过程中空洞边缘微小区域内会产生双向拉应力 ,直到闭合时拉应力才会变成压应力。压下方向的应变是绝对值最大的应变 ,主导着空洞的闭合过程。高温下的空洞闭合后能够立即完成再结晶过程 ,但空洞焊合需要一定的保温时间

Numerical simulation of Fore closure in solid cylinder under hot forging

The design of processing schedule to eliminate defects in steel forging is very important in the study of material processing. The closure of pore in solid cylinders during hot forging under various processing conditions is numerically simulated in this paper using FE software MARC. The stress and strain distribution and evolution during pore deformation are analyzed and various factors influencing the pore closure and welding are examined. The simulation results show that, there are tensile stresses in two directions during deformation in a small region along the pore and change to compression when pore closes. The strain component in the upsetting direction is the absolutely largest value and the leading factor on pore closure. At high temperature, the material at the closed pore quickly completes the recrystallisation, but it needs a long time to weld the pore closure for atom diffusion.