摘要
为研究激光螺旋点焊的断裂行为和断口特征,以期为高性能激光点焊的应用提供理论支持。采用振镜搭载机器人的激光螺旋焊接系统对1 mm厚汽车用高强钢进行焊接,设计了一种类阿基米德螺旋线扫描路径以使焊点热输入均匀分布,并对焊接接头的断裂行为进行分析。研究发现,在拉剪力的作用下,激光螺旋点焊主要发生的断裂失效形式为单面焊点撕出断裂和双面焊点撕出断裂,裂纹的萌生及扩展均是沿着熔合区和热影响区交界处。粗晶热影响的大角度晶界比例相对较少,为18.69%,KAM均值最大为0.65,存在的应力应变相对较大,使得裂纹更倾向于在粗晶热影响区萌生和扩展。
This article uses a laser spiral welding system equipped with a vibrating mirror and a robot to weld 1 mm high-strength steel for automobiles.In order to evenly distribute the heat input of the solder joint,a type of Archimedean spiral was designed,with an outer diameter of 5.0 mm for the scanning path.The spiral is composed of multiple semicircles and a 5πmm circular path on the periphery,R1=0.5 mm,R2=1.0 mm,R3=1.5 mm,R4=2.0 mm,R5=2.5 mm.The fracture behavior of laser spiral spot welding was analyzed,and the stress process,crack propagation path,and fracture surface during the tensile shear process of laser spiral spot welding were studied.Under the action of tensile and shear forces,the main fracture failure modes of laser spiral spot welding are single-sided weld tearing fracture and double-sided weld tearing fracture.The initiation and propagation of cracks are both along the boundary between the fusion zone and the heat affected zone.The proportion of large angle grain boundaries affected by coarse grain heat is relatively small at 18.69%,with a maximum KAM mean of 0.65.The stress and strain present are relatively large,making cracks more likely to initiate and propagate in the coarse grain heat affected zone.
作者
高紫豪
杨尚磊
毕军航
赵辛龙
田嘉伟
GAO Zihao;YANG Shanglei;BI Junhang;ZHAO Xinlong;TIAN Jiawei(School of Materials Science and Engineering,Shanghai University of Engineering Science,Shanghai 201620,China;Shanghai Laser Intelligent Manufacturing and Quality Inspection Professional Technical Service Platform,Shanghai 201620,China)
出处
《电焊机》
2024年第10期42-52,92,共12页
Electric Welding Machine
基金
上海市科委地方院校能力建设项目(20030500900)
上海市科委专业技术服务平台(21DZ2294200)。
关键词
激光螺旋点焊
汽车用高强钢
疲劳断裂
失效形式
扫描路径
laser spiral spot welding
high-strength steel for automobiles
fatigue fracture
failure modes
scan path
