深冷处理温度对镁合金MIG焊接接头组织与性能的影响  

Effect of Deep Cryogenic Treatment Temperature on the Microstructures and Properties of Magnesium Alloy MIG Welded Joint

作　　者：杨栋[1] 吴志生[2] 张立 高宇龙[1] YANG Dong;WU Zhi-sheng;ZHANG Li;GAO Yu-long(Teaching Center of Experiment and Practice,Shanxi Datong University,Datong 037003,China;College of Materials Science and Engineering,Taiyuan University of Science and Technology,Taiyuan 030024,China)

机构地区：[1]山西大同大学教学实验与实训中心,山西大同037003 [2]太原科技大学材料科学与工程学院,山西太原030024

出　　处：《材料保护》2021年第9期43-47,共5页Materials Protection

基　　金：山西大同大学校级青年科学研究项目(2018Q11)资助。

摘　　要：为解决镁合金在焊接时易使焊接接头软化的问题,对镁合金采用不同温度进行深冷处理,通过改变基体的微观组织,进而提高焊接接头的力学性能。结果表明:随着深冷温度的降低,晶内韧窝数量增多,晶粒尺寸变小,第二相粒子增多,各相衍射峰值增强,深冷处理后焊接接头的力学性能显著提高。其中,经过-190℃、12 h深冷处理后的镁合金MIG焊接接头的力学性能最佳,与未处理的焊接接头比较,其硬度、抗拉强度与伸长率分别提高了48.83%、8.02%和1.25%。In order to solve the problem that the magnesium alloy is easy to soften the welded joint during welding,the magnesium alloy was handled by the cryogenic treatment at different temperatures,and the mechanical properties of the welded joint were improved by changing the microstructure of the substrate.Results showed that with the decrease of cryogenic treatment temperature,the number of dimples in the crystal increased,the grain size decreased,the number of particles in the second phase increased,the diffraction peak value of each phase increased,and the mechanical properties of the welded joint improved significantly.Among them,the mechanical properties of the magnesium alloy MIG welded joint after-190℃,12 h cryogenic treatment were the best.Compared with the untreated welded joint,the hardness,tensile strength and elongation of the magnesium alloy MIG welded joint with best mechanical properties were increased by 48.83%,8.02%and 1.25%,respectively.

关 键 词：镁合金 深冷处理 焊接接头 微观组织 力学性能 

分 类 号：TG156.91[金属学及工艺—热处理]