汽车用镁/钢异种金属的焊接接头组织与性能研究  

Microstructure and properties of magnesium/steel dissimilar metals welded joint for automobile

作　　者：李文博[1] 何磊 汪小勇 Li Wenbo;He Lei;Wang Xiaoyong(Changchun Aulomohile Industry Inslilule,Changchun 130022, China;School of Materials Science and Engineering, Jilin University, Changchun 130012, China)

机构地区：[1]长春汽车工业高等专科学校,长春130022 [2]吉林大学,材料科学与工程学院,长春130012

出　　处：《焊接》2018年第11期11-15,65,共6页Welding & Joining

基　　金：国家自然科学基金资助项目(61475110)

摘　　要：采用熔化极惰性气体保护电弧焊(MIG)方法对AZ91D合金/Q345钢异种金属进行了焊接,研究了焊接电流和焊接速度对焊缝显微组织和焊接接头抗拉强度的影响。结果表明,不同焊接电流条件下焊缝区都为等轴晶,且随着焊接电流的增加,焊缝区晶粒尺寸逐渐增大;随着焊接电流的增加,焊接接头的抗拉强度呈现先增加而后降低的趋势,在焊接电流为130 A时取得最大值144 MPa;随着焊接速度的增加,异种金属焊接接头的抗拉强度呈现先增加后降低的特征,在焊接速度为750 mm/min时取得最小值,抗拉强度最小值约为38 MPa。AZ91D合金/Q345钢异种金属适宜的MIG焊接工艺为:焊接电流130 A,焊接速度600 mm/min。The dissimilar metals of AZ91D alloy/Q345 steel were welded by MIG welding process,and the effects of welding current and welding speed on the microstructures and tensile strength of welded joint were studied. The results show that,at different welding currents,the weld zone is made of equiaxed grain,and with the increase of welding current,the grain size of weld zone increases gradually,the tensile strength of welded joint increases firstly and then decreases,and the maximum value of 144 MPa was obtained at the welding current of 130 A. With the increase of welding speed,the tensile strength of welded joint increases firstly and then decreases,and the minimum value of 38 MPa was obtained at the welding speed of 750 mm/min. MIG welding process can be used to weld AZ91D alloy/Q345 steel dissimilar metals at welding current of 130 A and welding speed of 600 mm/min.

关 键 词：AZ91D合金/Q345钢 焊接电流 焊接速度 组织 力学性能 

分 类 号：TG407[金属学及工艺—焊接]