55CrSi弹簧断裂原因分析

为了找出材质为55CrSi泵下体内部弹簧的断裂原因,利用体视显微镜、扫描电子显微镜对断裂弹簧的裂纹形态及断口表面进行宏微观观察.结果表明:弹簧的断裂失效模式为疲劳断裂;裂纹起源于弹簧丝表面,是由弹簧丝制备及加工过程中形成的凹痕及折叠缺陷引起的;另外,弹簧丝表面喷丸质量较差,造成较大的应力集中,弹簧运行过程中,在交变载荷...

Fracture Cause Analysis of 55CrSi Springs

To investigate the fracture cause of the inner 55CrSi springs of the lower body of a pump, the crack and fracture surface morphology of the broken springs were observed by stereomicroscopy and scanning electron microscopy. The results show that the fracture mode of the springs is fatigue fracture, and the cracks originated from the surface of the spring wires, which was caused by the dent and folding defects formed during the preparation and processing of the spring wires. In addition, the surface shot peening quality of the spring wires was poor, resulting in greater stress concentration. During the operation of the springs, the fatigue cracks propagated inward from the surface of the spring wires under alternating load, finally leading to the fracture.