Cu-P-Cr-Ni-Mo耐候钢热变形过程的微观组织模拟

Microstructure simulation of a Cu-P-Cr-Ni-Mo weathering steel during hot deformation

基于热模拟试验数据,建立了Cu-P-Cr-Ni-Mo耐候钢的动态再结晶模型,并利用有限元软件Deform-3D对试验钢进行了热压缩过程以及微观组织的演变模拟。结果表明,在热压缩过程中,坯料内部存在不均匀变形,其心部大变形区的等效应变最大、温度最高,动态再结晶进行得最充分;不同工艺参数对动态再结晶体积分数与平均晶粒尺寸具有显著的影响,较高的变形温度、较低的应变速率和大应变均有利于动态再结晶的进行;试样不同区域的动态再结晶的体积分数随着应变的增大而升高,相应的平均晶粒尺寸随着应变的增加而减小。有限元软件Deform-3D模拟的微观组织演变规律与热模拟试验结果具有高度的一致性。

Mathematical model for dynamic recrystallization of a Cu-P-Cr-Ni-Mo weathering steel was established based on experimental data on a Gleeble-3500 simulator. Hot-compression procedure and microstructure evolution were simulated by a Deform-3D finite element software. The results show that inhomogeneous deformation exists in the samples during hot-deformation, the maximum equivalent strain and the highest temperature appeare in the center area of the sample with large deformation, in which the dynamic recrystallization completely occurs. The dynamic recrystallization volume fraction and mean grain size are obviously influenced by the processing parameters, namely, the dynamic recrystallization transformation can be promoted by higher deformation temperature, lower strain rate and larger strain. With strain increasing the volume fraction of dynamic recrystallization in different regions of the samples increases, on the contrary the mean grain size decreases. The microstructure evolution results achieved by Deform-3D simulation is highly consistent with the experimental results obtained by hot-simulation.