薄板耐候钢激光焊对接与搭接接头性能研究  

Research on the properties of laser welded butt joint and overlap joint of weathering steel sheet

作　　者：柴晋峰 张天倚 CHAI Jinfeng;ZHANG Tianyi(CRRC Dalian Co.,Ltd.,Dalian,Liaoning 116000,China)

机构地区：[1]中车大连机车车辆有限公司,辽宁大连116000

出　　处：《轨道交通材料》2025年第2期42-46,共5页Materials for Rail Transportation System

基　　金：中车大连公司科技立项(DL2023C0321)。

摘　　要：为提高耐候钢薄板车体的焊接质量,试验选用Q310NQL2激光焊对接接头与搭接接头(与Q460E搭接)进行了拉伸、弯曲、硬度与疲劳试验。试验结果表明:对接接头的拉伸与弯曲性能良好,搭接接头抗剪切强度为361.5MPa;对接接头与搭接接头硬度均呈M形分布,焊缝与熔合线处硬度较高,热影响区硬度值下降,母材硬度值较低;对接接头(保留余高)在指定寿命为1×107次循环下的中值疲劳极限为375 MPa,焊搭接接头在指定寿命为1×107次循环下的最大载荷水平为3420N;两种接头的疲劳断口形貌均具有典型疲劳断裂特征,不同的是对接试件终断区有典型的河流状花样或舌状花样,解理断裂的特征较明显,而搭接试件终断区断口形貌为大小、深浅不一的韧窝,为韧窝型韧性断裂。In order to improve the welding quality of railcar body made of weathering steel sheet,laser welded butt joints of Q310NQL2 and overlap joints of Q310NQL2 and Q460E sheet are selected for tensile,bending,hardness,and fatigue tests.The test results show that the tensile and bending properties of the butt joint are nice,and the shear strength of the overlap joint reaches 361.5 MPa;The hardness of the butt joints and lap joints presents M-shaped distribution,with higher hardness at the weld and fusion line,decreased hardness in the heat-affected-zone and lower hardness in the base metal;The median fatigue limit of the butt joint(keeping the rein⁃forcement)at the specified fatigue life of 1×107 loading cycles is 375 MPa,while the maximum load of the overlap joint at the specified life of 1×107 cycles is 3420 N;The fatigue fracture morphology of both types of joints feature a typical fatigue fracture.The difference is that the final fracture area at the butt joint specimen shows typical river-shaped or tongue-shaped patterns,and the cleavage fracture characteristics are obvious,while the fracture morphology of the final fracture area at the overlap joint specimen is a ductile fracture with varying sizes and depths of dimples.

关 键 词：薄板耐候钢 激光焊 对接接头:搭接接头 

分 类 号：U270.64[机械工程—车辆工程] TG456.7[交通运输工程—载运工具运用工程]