直升机桨叶安装螺栓根部断裂分析与改进  

Analysis and Improvement of Root Fracture Fault of Helicopter Blade Installation Bolt

作　　者：辛志文 毛永杰 张韶佳 XIN Zhi-wen;MAO Yong-jie;ZHANG Shao-jia(Changhe Aircraft Industries(Group)Co.,Ltd.,Jiangxi Jingdezhen 333000,China;Aviation Manufacturing College,Nanchang Aviation University,Nanchang 330053,China)

机构地区：[1]昌河飞机工业(集团)有限责任公司,江西景德镇333000 [2]南昌航空大学航空制造工程学院,南昌330063

出　　处：《失效分析与预防》2023年第5期326-334,共9页Failure Analysis and Prevention

基　　金：江西省科技厅重点研发计划(20203BBE53049)。

摘　　要：针对直升机桨叶安装螺栓根部断裂的故障,综合利用宏观形貌分析、显微观测及理化检验等手段,对其断裂原因进行分析,并提出改进措施。结果表明:桨叶安装螺栓根部断裂为沿晶脆性断裂,其内部残余应力主要产生于冷挤压成形过程,退火软化的状态下在螺栓根部R区磨削后产生划痕并在后续工序中进一步扩展成显微裂纹,以致在电镀镉过程中产生氢致裂纹,最终发生疲劳断裂;通过增加冷挤压成形模具控制措施、冷挤压后热处理去应力工序及调整磁粉检测、热处理工序顺序能够有效改善产品质量,进而提高飞行安全性能。In response to the root fracture of the installation bolt of helicopter blade,a comprehensive analysis was conducted using macroscopic morphology characterization,microscopic observation,and physical and chemical inspection methods to analyze the cause of the fracture and propose improvement measures.The analysis results show that the root fracture of the blade installation bolt is intergranular brittle fracture,and its internal residual stress is mainly generated during the cold extrusion forming process.Under the state of annealing softening,scratches are generated in the R zone of the bolt root after grinding and further expand into microcracks in subsequent processes,resulting in hydrogen-induced cracks during the cadmium plating process and ultimately fatigue fracture.In the light of analysis results,by adding control measures for cold extrusion forming molds,stress relieving processes after cold extrusion heat treatment,and adjusting the sequence of magnetic particle and heat treatment processes,the product quality can be effectively improved as well as the flight safety.

关 键 词：桨叶安装螺栓 沿晶脆性断裂 残余应力 氢致裂纹 冷挤压 

分 类 号：TG115.2[金属学及工艺—物理冶金]