摘要
利用万能材料拉伸试验机、显微硬度计、金相显微镜、扫描电镜、透射电镜、能谱仪等设备研究了6A01-T5铝合金MIG焊接接头的微观组织与力学性能,重点针对其软化行为进行了分析。结果表明,焊缝心部为等轴晶的典型铸态组织,靠近熔合线附近的焊缝为柱状晶组织。在距离两侧熔合线约6 mm处的热影响区均存在一软化区,为焊接接头的最薄弱区。焊接接头抗拉强度159 MPa,断后伸长率10.2%,断裂位置为硬度最低的软化区。软化区受焊接热影响产生过时效作用,Mg2Si析出相聚集长大是导致该区域硬度降低的主要因素。
The microstructures and mechanical properties of metal inert gas(MIG)welded joints of 6A01-T5 aluminum alloy were investigated by tensile testing machine,micro-hardness tester,optical microscope(OM),scanning electron microscope(SEM),transmission electron microscope(TEM)and energy dispersive spectroscopy(EDS),its softening behavior was analyzed particularly.The results show that the microstructure of weld zone is a typical equiaxial as-cast microstructure,the columnar grains form near the fusion line.Softened regions exist in the two side of heat-affected zone(HAZ)6 mm far away from fusion line which are the weakest zone of the welded joint.The tensile strength of the welded joint is 159 MPa,and the elongation after fracture is 10.2%.And the location of the fracture is the softened zone with lowest hardness.The softening zone is over-aged under the influence of welding heat,and the Mg2Si precipitates grow,which is the main factor of hardness reduction in this area.
作者
毛镇东
郑自芹
李帅贞
韩晓辉
梁景恒
徐智宝
MAO Zhendong;ZHENG Ziqin;LI Shuaizhen;HAN Xiaohui;LIANG Jingheng;XU Zhibao(CRRC Qingdao Sifang Co.,Ltd.,Qingdao 266111,China;Yantai Branch of China North Industries Group Corporation No.52 Institute Co.,Ltd.,Yantai 264003,China)
出处
《热加工工艺》
北大核心
2021年第1期35-39,共5页
Hot Working Technology
作者简介
毛镇东(1987-),男,浙江江山人,硕士,主要从事轨道车辆车体焊接制造技术及工艺研究,电话:17852619667,E-mail:maozhendong2018@163.com。
