热压缩变形不均匀性的有限元模拟与试验研究

FEM Analysis and Experimental Study of Deformation Nonuniformity After Hot Compression

用FEM方法对一种共析珠光体钢经700℃、0．1～10s^-1的热压缩变形过程进行了数值模拟，分析了变形后试样纵剖面上等效应变与应变速率的分布情况，确定了实际变形条件与试验设定条件比较一致的区域范围，并通过相应的显微组织变化进行了验证。结果表明，热压缩变形试样心部的等效应变与应变速率比设定值大40％左右，而端面值则为设定值的1／5-1／4；在从试样端面到中心距离的Z／5-3／5区域内，实际应变及应变速率与试验设定的变形条件基本一致，且1／Z处一致性最好。

The hot compression of an eutectoid pearlite steel at 700 ℃ was simulated with finite element method （FEM） at a strain rate from 0.1 to 10.0 s ^-1. The distribution of efficient strain and strain rate in axial section of deformed samples was analyzed. The coincident region of practical with set conditions was determined and approved by metallographie examination. The results indicate that the efficient strain and strain rate are higher by about 40% than in the center of deformed samples, but are about 1/5-1/4 of set values at the end surface; The practical strain and strain rate accord with the set values at 2/5-3/5 distance from the end surface to the center of deformed sample, and the consistency between practical and set values is reached at 1/2 distance from the end surface to the center.