SMA490BW钢双丝焊接头组织及力学性能研究  

Study on Microstructures and Mechanical Properties of SMA490BW Steel Double Wire Welded Joints

作　　者：孙中文[1] 吴向阳[2] 张志毅[2] 何永攀 李远星[3] 陈辉[3] 

机构地区：[1]济南铁路局青岛机车车辆监造项目部,山东青岛266111 [2]南车青岛四方机车车辆股份有限公司技术工程部,山东青岛266111 [3]西南交通大学焊接研究所,四川成都610031

出　　处：《热加工工艺》2016年第11期55-58,共4页Hot Working Technology

摘　　要：对SMA490BW钢进行双丝MAG焊接,并研究了接头组织及力学性能。结果表明,SMA490BW钢双丝焊焊缝成型美观,无未熔合、夹渣等焊接缺陷。焊缝各层组织有差异,上层组织主要为先共析铁素体、针状铁素体、条状铁素体和粒状贝氏体组织;中层柱状晶组织有细化趋势;底层出现过热的魏氏组织。接头硬度和抗拉强度满足生产要求,焊接残余应力较小,接头疲劳性能优良,疲劳极限可达到420 MPa。Double-wire MAG welding of SAM490 BW steel was carried out. Microstructures and mechanical properties of the joints were researched. The results show that SMA490 BW steel double-wire welded joints own beautiful forming without incomplete fusion, slag and other welding defects. Microstructures in weld layers are different, proeutectoid ferrite,acicular ferrite, strip ferrite and granular bainite are observed in the top layer. Refined grains can be found out in the middle layer owing to destruction of columnar crystals. Overheating widmanstatten can be clearly observed in the bottom layer.Welding residual stress is lower. Hardness and tensile strength of joints meet production requirements.Welded joints own good fatigue performance and fatigue limit can reach 420 MPa.

关 键 词：SMA490BW钢 双丝MAG焊 组织 力学性能 

分 类 号：TG457.11[金属学及工艺—焊接]