1.Testing Center, Jiangyin Xingcheng Special Steel Co., Ltd., Jiangyin 214429, China;
2.The Fourth Military Representative Office of the Army Equipment Department in Taiyuan, Taiyuan 030002, China
Abstract：One company purchased 52CrMoV4 materials to manufacture train suspension springs. During the maintenance process of the freight car after service for a period of time, the cracking of one suspension spring was observed. Therefore, this suspension of the train was disassembled for sampling. The failed spring was comprehensively analyzed by physical and chemical inspection, metallographic analysis, mechanical properties and fracture scanning. The results show that all technical indexes of the train spring can meet the design requirements. Finally, the fracture of spring was observed and analyzed by scanning electron microscope (SEM). It was found that the failure mechanism of the spring fracture belonged to fatigue fracture, and the fracture source was at the surface contact point of the spring. During the backandforth operation of spring, the contact wear point between two adjacent springs expanded and deteriorated gradually, thus eventually causing the fracture of spring.
2022, Vol. 40 
