电气屏柜吊耳铝型材焊接接头组织与性能研究  

Microstructure and properties of the welded joint on aluminum profilefor the lifting lug on electric screen cabinet

作　　者：剡苏荣 袁翔 刘雄 丁浩 王向东 谢紫华 YAN Surong;YUAN Xiang;LIU Xiong;DING Hao;WANG Xiangdong;XIE Zihua(CRRC Zhuzhou Electric Locomotive Research Institute Co.,Ltd.,Zhuzhou,Hunan 412001,China)

机构地区：[1]中车株洲电力机车研究所有限公司,湖南株洲412001

出　　处：《轨道交通材料》2023年第6期68-72,共5页MATERIALS FOR RAIL TRANSPORTATION SYSTEM

基　　金：中车株洲电力机车研究所有限公司重大科研项目“机动城柜体典型构件可靠性研究”(K10TZ20P0500)。

摘　　要：文章采用MIG焊对电气屏柜吊耳用6005A-T6铝型材进行焊接工艺研究,并分析不同焊接参数下的接头焊缝成形、微观组织、常规力学性能以及耐蚀性能。结果表明:6005A铝合金对于焊接热输入具有较大的敏感性,随着焊接电流的逐渐增加,接头焊缝成形良好,接头抗拉强度(UTS)、屈服强度(YS)呈现先增大后减少,在(200±10)A时达到最大值,分别为250 MPa、211 MPa。接头硬度呈近W形对称分布,热影响区硬度最低,而靠近焊缝中心硬度稍有增加。接头热影响区由于晶界的粗化、第二相β′(Mg_(2)Si)在晶界处连续分布具有较低的耐晶间腐蚀性能,是接头在服役过程中最弱的区域。室温及高温下的焊接接头应力腐蚀敏感指数分别为3.5%和3.7%,表明具有较高的抗应力腐蚀性能。This paper studies the application of MIG techniques in the welding process of 6005A-T6 aluminum profiles used for the lifting lugs on electrical screen cabinets,and analyzes the welded joint formation,microstructure,conventional mechanical properties,and corrosion resistance under different welding parameters.The results indicate that 6005A aluminum alloy is quite sensitive to welding heat input.With the gradual increase of welding current,the joint is well formed,and the joint tensile strength(UTS)and yield strength(YS)increase first and then decrease,reaching the maximum values of 250 MPa and 211 MPa respectively at(200±10)A.The hardness of the joint exhibits a nearly W-shaped symmetrical distribution,with the lowest hardness in the heat affected zone and a slight increase of hardness near the center of the weld.Due to the coarsening of grain boundaries and the continuous distribution of the second phaseβ'(Mg_(2)Si)at the grain boundaries,the heat-affected zone of the joint has a low intergranular corrosion resistance,forming the weakest area in the service process of the joint.The stress corrosion sensitivity index of the welded joints at room temperature and high temperature is 3.5%and 3.7%respectively,indicating a high stress corrosion resistance.

关 键 词：6005A铝合金 MIG焊 微观组织 耐蚀性能 电气屏柜 

分 类 号：U270.3[机械工程—车辆工程] U270.64[交通运输工程—载运工具运用工程]