Mechanism of necking defect of 6082 aluminium alloy rolled by cross-wedge rolling method based on material thermal properties  

基于材料热性能的楔横轧轧制6082铝合金轴的颈缩机理

作　　者：WANG Dong-gang SHU Xue-dao WANG Rui XU Sheng 王东钢;束学道;汪锐;徐生(Faculty of Mechanical Engineering&Mechanics,Ningbo University,Ningbo 315211,China;Institute of Mechanical and Electrical Engineering,Zhejiang Business Technology Institute,Ningbo 315012,China;Zhejiang Provincial Key Laboratory of Part Rolling Technology,Ningbo 315012,China)

机构地区：[1]Faculty of Mechanical Engineering&Mechanics,Ningbo University,Ningbo 315211,China [2]Institute of Mechanical and Electrical Engineering,Zhejiang Business Technology Institute,Ningbo 315012,China [3]Zhejiang Provincial Key Laboratory of Part Rolling Technology,Ningbo 315012,China

出　　处：《Journal of Central South University》2020年第12期3721-3732,共12页中南大学学报（英文版）

基　　金：Project(51975301)supported by the National Natural Science Foundation of China;Project(LZ17E050001)supported by the National Natural Science Foundation of Zhejiang Province of China。

摘　　要：Necking defects have long troubled the application of cross-wedge rolling technology in aluminium alloy shaft parts.To accurately predict necking defects,new judgement conditions are established based on the thermal performance of 6082 aluminium alloy.The limit-sectional shrinkage without necking defects is achieved by combining theoretical calculation and finite-element model analysis,which couples heat transfer and deformation.In this paper,a 6082 aluminium alloy extruded rod with a 40 mm diameter rolled at a preheated temperature of 500℃and a rolling angular velocity of 1 rad/s is taken as an example.The simulation and experimental results show that necking defects do not occur on the rolled pieces if the sectional shrinkage is below the limit-sectional shrinkage but will occur when the sectional shrinkage is above it.The results prove that the prediction model of necking defects in cross-wedge rolling of 6082 aluminum alloy is feasible,and this research provides a theoretical basis for the qualified aluminum alloy shafts produced by the cross-wedge rolling.铝合金轴类零件在楔横轧工艺中的颈缩缺陷长期困扰着该技术在实际生产中的应用。为准确预测颈缩缺陷发生时的极限断面收缩率,建立了新的基于6082铝合金热性能的颈缩缺陷判断模型,即通过理论计算与热-机耦合的有限元模型相结合的方式,实现极限断面收缩率的预测。本文以直径为40 mm的6082铝合金挤压棒为例,模具展宽角和成形角不变,在预热温度为500°C及轧辊角速度为1 rad/s的条件下,对不同断面收缩率下的楔横轧的仿真与试验结果进行了分析。仿真和实验结果表明,断面收缩率低于极限断面收缩率时,铝合金轴件上没有出现缩颈缺陷;断面收缩率高于极限断面收缩率时,出现了铝合金轴缩颈缺陷。该结果证明了6082铝合金楔横轧颈缩缺陷的预测模型是可行的,该研究为楔横轧轧制合格的铝合金轴件提供了理论依据。

关 键 词：6082 aluminium alloy cross wedge rolling limit-sectional shrinkage necking mechanism temperature field 

分 类 号：TG339[金属学及工艺—金属压力加工]