不同形状的耐候钢T形角接接头疲劳性能研究  

Research on Fatigue Properties of Weathering Steel T-shaped Fillet Joints with Different Shapes

作　　者：黄显峰 韩景茹 黄君辉 黄风龙 暴兴威 HUANG Xianfeng;HAN Jingru;HUANG Junhui;HUANG Fenglong;BAO Xingwei(CRRC Qiqihar Vehicle Co.,Ltd.,Qiqihar 161002,China;Materials Science and Engineering,Dalian Jiaotong University,Dalian 116028,China)

机构地区：[1]中车齐齐哈尔车辆有限公司,黑龙江齐齐哈尔161002 [2]大连交通大学材料科学与工程学院,辽宁大连116028

出　　处：《电焊机》2024年第1期114-119,共6页Electric Welding Machine

摘　　要：T形角接接头在铁路货车箱型结构中应用较为广泛,该接头处受力较为复杂,其疲劳性能对于整车安全有着关键作用。对不同形状Q450NQR1高强度耐候钢多层多道焊T形角接接头进行三点弯曲疲劳试验和疲劳断口扫描试验。结果表明:a10角焊缝、向外凸焊缝与向内凹焊缝焊接接头的中值疲劳极限由高到低依次为289 MPa、277.5 MPa、241 MPa。疲劳试件分别在焊趾或焊缝之间启裂,焊趾处裂纹向母材延伸。观察其断口形貌可知:各区域具有典型疲劳断裂特征,启裂区存在同扩展方向一致的清晰细密的条纹,此种条纹是一种呈向外放射状且具有一定高度差的撕裂棱。扩展区随疲劳循环次数的增加而扩大,裂纹呈河流状分布,终断区观察到大小深浅不一的韧窝,故判断断口为韧窝型韧性断裂。As a common welded joint,T-shaped corner joint is widely used in railway freight box structure.The force of the joint is complicated,and the fatigue performance of the joint plays a key role in the safety of the vehicle when the truck is running.Three point bending fatigue tests and fatigue fracture scanning tests have been carried out on T-shaped Angle joint of Q450NQR1 high strength weathering steel with different shapes.The test results show that the median fatigue limits of a10 fillet weld,outward convex weld and inward concave weld are 289MPa,277.5MPa and 241MPa from high to low.The fatigue specimens were cracked between the weld toe or weld respectively,and the crack at the weld toe extended to the base metal.By observing the fracture morphology,it can be seen that each region has typical fatigue fracture characteristics,and there are clear and fine stripes in the fracture initiation zone in the same direction as the expansion.This stripe is a kind of outward-radiating tearing edge with a certain height difference.The expansion zone expanded with the increase of fatigue cycles,the cracks were distributed like rivers,and dimples of different sizes and depths were observed in the final fault zone,so it was judged that the fracture was dimple-type ductile fracture.

关 键 词：高强度耐候钢 角接接头 三点弯曲 疲劳性能 

分 类 号：TG457[金属学及工艺—焊接]