摘要
对断裂的60 kg/m U75V钢轨闪光焊接头进行了宏观形貌观察、断口扫描电镜观察及能谱分析、显微组织观察和材质分析试验,分析其断裂原因。结果表明:闪光焊接头断裂性质为疲劳断裂;由于打磨不当在轨底下表面形成白层马氏体组织,在拉应力作用下裂纹由马氏体组织处萌生并扩展,最终导致闪光焊接头横向断裂。焊接施工人员用打磨方式清除焊缝表面缺陷时应控制好单次打磨量,避免产生马氏体组织。
The fracture causes of the 60 kg/m U75V rail flash welding joint were analyzed by macroscopic morphology observation,fracture scanning electron microscope observation,energy spectrum analysis,microstructure observation and material analysis test.The results show that the fracture property of flash welding joint is fatigue fracture.Due to improper grinding,white layer martensite structure is formed under rail surface,and the crack initiates and expands from the martensite structure under the action of tensile stress,which eventually leads to the transverse fracture of the flash welding joint.When welding construction personnel remove weld surface defects by grinding,they shall control the amount of single grinding to avoid martensite structure.
作者
许鑫
杨其全
钟进军
吕晶
张倩
王玉婷
王雪娜
XU Xin;YANG Qiquan;ZHONG Jinjun;LYU Jing;ZHANG Qian;WANG Yuting;WANG Xuena(Metals and Chemistry Research Institute,China Academy of Railway Sciences Corporation Limited,Beijing 100081,China;Track Maintenance Department,China Railway Shanghai Group Co.Ltd.,Shanghai 200071,China)
出处
《铁道建筑》
北大核心
2022年第5期59-62,共4页
Railway Engineering
基金
中国国家铁路集团有限公司科技研究开发计划(K2020G015)
中国铁道科学研究院集团有限公司基金(2020YJ195)。
关键词
钢轨
闪光焊接头
试验研究
马氏体组织
疲劳断裂
打磨量
rail
flash welding joint
experimental research
martensite structure
fatigue fracture
grinding amount
作者简介
第一作者:许鑫(1987-),女,助理研究员,硕士。E-mail:13810628917@163.com。
