某液压起重机活塞杆断裂失效分析

Fracture Failure Analysis of Piston Rod of a Hydraulic Crane

针对液压起重机缸的活塞杆在使用过程中发生的断裂失效,采用扫描电子显微镜（SEM）、能谱仪和硬度检测仪等方法研究了断口形貌及局部位置的成分进行了分析,确定了裂纹源的位置和形成机理,并对断裂的原因进行了分析。结果表明：钢中的非金属氧化物夹杂、第二相粒子是活塞杆疲劳断裂的的主要裂纹源。活塞杆在交变载荷的作用下,在缺口敏感度较高的螺纹切口处产生疲劳断裂。

According to the fracture failure of the piston rod in a hydraulic crane in running process, the fracture morphologies and the composition of local region were analyzed by using SEM, energy spectrometer and hardness tester, and the position and formation mechanism of the crack source were determined, and the cause of the fracture was analyzed. The results show that the non-metallic oxide inclusions, and the second phase particles are the main crack source of fatigue fracture of the piston rod. Under the action of alternating load, the fatigue fracture of the piston rod occurs at the thread incision with high notch sensitivity.