摘要
高架桥用42CrMoA高强度双头螺栓在服役期间发生螺纹断裂现象,通过外观检查、化学成分分析及扫描电镜分析等手段,对其断裂原因进行了分析。结果表明,螺栓在冶炼过程中成分控制不严,在安装中质量不达标,紧固力不均匀或预紧力不足造成螺栓在螺纹处出现缝隙或间隙,在腐蚀环境下发生缝隙腐蚀。在闭塞腐蚀电池及应力集中作用下加速溶解金属基体,在缝隙腐蚀的阳极端部形成裂纹源。裂纹在腐蚀和疲劳的双重作用下,使裂纹不断向纵深扩展,直至螺栓断裂。安装质量不达标且冶炼工艺控制不严是引发螺栓断裂的关键因素。
The 42CrMoA high-strength stud bolt used for viaduct has thread fracture during service.The reason for fracture was analyzed by means of appearance examination,chemical composition analysis and scanning electron microscope analysis.The results show that the components of bolts are not strictly controlled in the smelting process,the quality is not up to standard in the installation process,and the uneven tightening force or insufficient pre-tightening force cause cracks or gaps in the threads of bolts,and crevice corrosion occurs in the corrosive environment.Under the action of occluded corrosion cell and stress concentration,the dissolution of metal matrix is accelerated,and the crack source is formed at the anode end of crevice corrosion.Under the dual effects of corrosion and fatigue,the crack will continue to expand in depth until the bolt breaks.The key factors leading to bolt fracture are that the installation quality is not up to standard and the smelting process is not strictly con‐trolled.
作者
孟海燕
袁凯琴
刘刚
Meng Haiyan;Yuan Kaiqin;Liu Gang(School of Science and Technology,Nanchang Hangkong University,Gongqingcheng 332020,China;School of Materials Science and Engineering,Nanchang Hangkong University,Nanchang 330063,China)
出处
《电镀与精饰》
CAS
北大核心
2024年第1期70-78,共9页
Plating & Finishing
关键词
螺栓
裂纹
应力
腐蚀疲劳
断裂失效
bolt
crack
stress
corrosion fatigue
fracture failure
作者简介
孟海燕(1979-),女,硕士,讲师,email:menghy2005@tom.com;通信作者:刘刚,email:liugang0915@126.com。
