径锻压下率对镁棒热力参数及组织演变的影响  

Effect of Radial Forging Reduction Rate on Thermodynamic Parameters and Microstructure Evolution of Magnesium Alloy Bar

作　　者：邹景锋 马立峰[1] 朱艳春[1] ZOU Jing-feng;MA Li-feng;ZHU Yan-chun(School of Mechanical Engineering,Taiyuan University of Science and Technology,Taiyuan 030024,China)

机构地区：[1]太原科技大学机械工程学院,太原030024

出　　处：《精密成形工程》2021年第6期84-90,共7页Journal of Netshape Forming Engineering

基　　金：国家自然科学基金(U1910213,51501122);山西省重点研发计划(201903D121088)。

摘　　要：目的通过径向锻造工艺制备大尺寸镁合金棒料,并研究ZK60镁合金稳定变形区轴向截面边部位置的组织演变规律。方法基于轴对称模型,利用数学解析方法建立不同压下率下的镁棒应变分量数学模型;使用弹塑性有限元分析软件对不同压下率下的镁棒径锻过程进行热力耦合分析;采用GFM-SSP32径锻机对铸态ZK60镁合金棒材进行阶梯锻造实验。结果随着径向压下量的增大,晶粒细化明显。当压下率达到62.29%时,孪生动态再结晶机制开动;与模拟结果相比,数学模型预测的平均相对误差约为8.4%,可较准确表征径锻镁棒的应变分布情况。结论径向锻造工艺完全可以制备ZK60镁合金棒材,并可有效解决镁合金塑性变形过程中的易开裂、散热快等问题。This paper aims to prepare the large-size magnesium alloy bar through radial forging process and study the microstructure evolution of the axial section edge in the stable deformation zone of ZK60 magnesium alloy. Based on the axisymmetric model, a mathematical model of the strain components of magnesium rods with different reduction rates was established by the mathematical analysis method;the thermal coupling analysis was carried out for the radial forging process of magnesium bars with different reduction rates by the elastic-plastic finite element analysis software;the step forging experiment was carried out on the cast ZK60 magnesium alloy bars by the GFM-SSP32 radial forging machine. The results showed that the grain refinement is obvious with the increase of radial reduction, and the twinning dynamic recrystallization mechanism is turned on when the depression rate reaches 62.29%;compared with the simulation results, the average relative error predicted by mathematical model is about 8.4%, which can more accurately characterize the strain distribution of the radial forging magnesium bars.The radial forging process can completely prepare ZK60 magnesium alloy bars, and effectively solve the problems of easy cracking and fast heat dissipation during the plastic deformation of magnesium alloy.

关 键 词：镁合金 径向锻造 热力参数 组织演变 

分 类 号：TG314.3[金属学及工艺—金属压力加工]