基于FEM分析轧制预变形对AZ31B镁合金热轧板材边部损伤的影响规律  

Edge Damage of Hot Rolled AZ31B Magnesium Alloy Sheets with Pre-Rolling Based on FEM

作　　者：齐艳阳 刘江林 王涛 高翔宇 任忠凯 Qi Yanyang;Liu Jianglin;Wang Tao;Gao Xiangyu;Ren Zhongkai(College of Mechanical and Vehicle Engineering,Engineering Research Center of Advanced Metal Composites Form-ing Technology and Equipment,Ministry of Education,TYUT-UOW Joint Research Center,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]太原理工大学机械与运载工程学院,先进金属复合材料成形技术与装备教育部工程研究中心,中澳联合研究中心,山西太原030024

出　　处：《稀有金属》2022年第7期873-881,共9页Chinese Journal of Rare Metals

基　　金：国家自然科学基金重点项目(U1710254,52075359);山西省科技重大专项项目(20181102011);中国博士后科学基金项目(2020M670710);山西省基础研究计划项目(20210302123103,20210302124115)资助。

摘　　要：基于FEM(finite element method)研究了轧制预变形对AZ31B镁合金热轧板材边部损伤的影响规律。选用Normalized Cockcroft&Latham损伤模型,在轧制温度为400℃、轧制速度为0.5 m·s^(-1)的条件下,对规格为50 mm×20 mm×15 mm的AZ31B镁合金板材预先使用凸度轧辊制备不同形状的板坯,使板坯中部的变形量一致,边部比中部分别高出2,4和6 mm,然后分别进行多道次、小压下率和单道次、大压下率平辊轧制模拟仿真。结果表明,轧制预变形能够显著降低镁合金板材边部的损伤,经多道次轧后板材边部的拉应力减小,应力三轴度降低,边部与中部的应变差值减小,边部金属与中部金属流动趋于同步,且在预设仿真方案范围内边部凸度越大,轧后板材边部的损伤值越小,最小损伤值为0.729。对镁合金板材预变形后可实现单道次、大压下率轧制,板材的边部温度和应变速率均有所增加,有利于降低轧制过程中的边部损伤。研究结果可为少或无边裂镁合金板材轧制工艺制定提供理论依据。Magnesium alloy is one of the key metal structural materials developed in recent years.It has the advantages of light weight,high specific strength,and large elastic modulus.It also has good shock absorption,noise reduction and impact resistance,economics and industrial production.It is of great significance to carry out in-depth research on key technical problems of magnesium alloys to solve the outstanding problems of the current energy structure and industrial structure.Rolling is one of the common methods for producing magnesium alloy sheets.This production process can refine the microstructure of magnesium alloy sheets,improve their mechanical properties,and has the advantage of continuous mass production.However,the magnesium alloy sheet is prone to edge cracks during the rolling process,and the resulting large amount of trimming waste seriously affects the yield and material utilization rate,which limits the further development of the material.Aiming at the problem of edge cracks during the rolling process of magne⁃sium alloy sheets,in recent years,many scholars have adopted methods such as on-line heating,cladding rolling,lining rolling,asyn⁃chronous rolling,prefabricated crown,model prediction,etc.These techniques have been validated effectively in the laboratory.This provides the possibility to prepare magnesium alloy sheets with no edge cracks or less edge cracks,and its industrial production will bring huge economic benefits.However,these technologies have process or equipment complexity,which brings certain difficulties to actual production.Whether pre-deformation affects the damage evolution at the edge of magnesium alloy sheets and how it affects the edge damage should be focused.Firstly,simulation schemes with different pre-deformation degrees were designed.On the basis of veri⁃fying the correctness of the finite element model,several sets of simulation schemes were carried out to analyze the changes of physical quantities such as tensile stress,stress triaxiality and plastic strain,explorin

关 键 词：AZ31B镁合金 预变形 有限元(FEM) 边部损伤 

分 类 号：TG335.1[金属学及工艺—金属压力加工]