U71Mn钢闪光-摩擦复合焊接头组织及性能研究  

Research on microstructure and properties of flash-friction hybrid welded joints of U71Mn steel

作　　者：王守明 高振坤 陈建华 丁韦 许蕊 刘国庆 谭锦红 WANG Shouming;GAO Zhenkun;CHEN Jianhua;DING Wei;XU Rui;LIU Guoqing;TAN Jinhong(China Academy of Railway Sciences,Beijing 100081,China;Institute of Metals and Chemistry,China Academy of Railway Sciences Group Co.,Ltd.,Beijing 100081,China;China Railway Xi'an Group Co.,Ltd.,Xi'an 710018,Shannxi,China;Beijing Jiaotong University,Beijing 100091,China;China Railway Xi'an Group Co.,Ltd.,Kunming 650011,Yunnan,China)

机构地区：[1]中国铁道科学研究院,北京100081 [2]中国铁道科学研究院集团有限公司金属及化学研究所,北京100081 [3]中国铁路西安局集团有限公司,陕西西安710018 [4]北京交通大学,北京100091 [5]中国铁路昆明局集团有限公司,云南昆明650011

出　　处：《金属加工(热加工)》2025年第4期67-73,78,共8页MW Metal Forming

摘　　要：闪光焊(Flash Butt Welding,FBW)以其高效优良的特性广泛应用于钢轨焊接,但目前其焊接接头存在灰斑缺陷、焊缝脱碳等问题仍无法彻底解决,针对该问题开发闪光-摩擦复合焊(Flash-Friction Hybrid Welding,F-FHW)。通过对U71Mn钢采用F-FHW进行焊接,并与FBW进行对比,研究两种焊接方法在显微组织、温度场与性能方面的影响规律。结果表明:F-FHW的焊缝可获得接近母材的金属显微组织;FBW焊缝的晶粒度为1级,晶粒直径平均约为350μm,而F-FHW为2.5级,晶粒直径平均约为200μm;闪光焊焊接焊缝高温聚集于中心部位,F-FHW焊接温度场高温区分布更均匀;FBW焊缝硬度存在明显的下降且略低于母材,F-FHW接头硬度分布均匀且高于母材。FBW焊缝冲击断口形貌为解理面+少量韧窝,并发现少量灰斑,F-FHW焊缝冲击断口形貌为解理面且未发现灰斑。Flash butt welding(FBW) is widely used in rail welding because of its high efficiency and excellent characteristics.However,there are still some problems in the welded joints,such as gray spot defects and weld decarburization,which can not be completely solved.To address this problem,flash-friction hybrid welding(F-FHW)has been developed.In this paper,U71Mn steel was welded by flash-friction hybrid welding,and compared with flash welding,and the influence laws of the two welding methods on the microstructure,temperature field and properties were studied.The results indicate that the weld of F-FHW welding can obtain a metal microstructure close to that of the base metal;The grain size of flash weld is grade 1 with an average grain diameter of about 350μm,while F-FHW is grade 2.5 with an average grain diameter of about 200μm.The high temperature of the FBW welding is concentrated in the central area,and the distribution of the high temperature zone in the F-FHW welding temperature field is more uniform;The hardness of FBW shows a significant decrease and is slightly lower than that of the base material,while the hardness distribution of F-FHW joints is uniform and higher than that of the base material.The impact fracture morphology of FBW weld is cleavage plane with a small amount of toughness dimples,and a small amount of gray spots are found.The impact fracture morphology of F-FHW weld is cleavage plane and no gray spots are found.

关 键 词：闪光-摩擦复合焊 闪光焊 显微组织 温度场 硬度 冲击 

分 类 号：TG457.1[金属学及工艺—焊接]