42CrMo高强度螺栓断裂失效分析  

Fracture Failure Analysis of 42CrMo High Strength Bolt

作　　者：陶鑫 钱建国[1] 王涛 计谦 TAO Xin;QIAN Jian-guo;WANG Tao;JI Qian(Nanjing Changjiang Electronics Group Co.,Ltd,Nanjing 210038,Jiangsu,China;The 28th Research Institute of China Electronics Technology Group Corporation,Nanjing 210007,Jiangsu,China)

机构地区：[1]南京长江电子信息产业集团有限公司,江苏南京210038 [2]中国电子科技集团公司第二十八研究所,江苏南京210007

出　　处：《机械研究与应用》2025年第2期152-155,共4页Mechanical Research & Application

摘　　要：某型雷达方位驱动系统在安装四点接触球式回转支承并进行螺栓装配旋拧过程中,1根10.9级高强度螺栓发生了断裂。为了研究断裂问题的内在机理,该文对此失效螺栓开展了失效分析。分析发现,螺栓的化学成分、金相检测与硬度检测均无异常;断口的电镜扫描结果显示,中心源区、扩展区与边缘瞬断区分别呈轴状韧窝、四周放射扩展与韧窝特征,表现为拉伸荷载下的过载断裂。经预紧应力分析认为,表面处理方式与润滑状况的不同导致了摩擦系数的差异,加之电动定力矩扳手二次旋拧会产生较大拧紧力矩,进而导致螺栓断裂。最终,通过调整螺栓拧紧力矩并采用星形顺序三步法紧固可有效解决螺栓断裂失效问题。During the bolt assembly and screwing process of installing the four-point contact ball slewing bearing for a certain type of radar azimuth drive system,one high-strength bolt of grade 10.9 fractured.To study the inherent mechanism of this problem,the failure analysis was carried out on the failed bolt.The chemical composition,metallographic examination,and hardness test of the bolt all showed no abnormality.The scanning electron microscopy of the fracture surface revealed that the central source area,the propagation area,and the edge transient rupture area exhibited axial dimples,radial propagation,and dimple characteristics respectively,indicating an overload fracture under tensile loading.Through the pre-tightening stress analysis,it is believed that differences in surface treatment methods and lubrication conditions can lead to differences in friction coefficients,and the secondary screwing of the electric torque wrench can generate a larger tightening torque.This problem can be solved by adjusting the bolt tightening torque and fastening it in a three-step method according to a star-shaped sequence.

关 键 词：高强度螺栓 失效分析 预防措施 电动定力矩扳手 

分 类 号：TH131.3[机械工程—机械制造及自动化]