基于低成本理念研究了铁路用38Si7弹簧钢的疲劳断裂行为。结果表明,弹条的显微组织、化学成分和硬度值均符合相关的标准要求,表明其断裂失效和材料自身没有关系。而导致疲劳断裂的原因是断裂位置应力集中较大,且有凹坑缺陷,导致疲劳裂纹的产生和裂纹扩展。 Based on the concept of low cost, the fatigue fracture behavior of 38Si7 spring steel for railways was studied. The results show that the microstructure, chemical composition and hardness of the bar comply with the relevant standard requirements, indicating that the fracture failure is not related to the material itself. The reason of the fatigue fracture is that the stress concentration at the fracture site is larger and the pit defect occurs, which leads to the generation of fatigue cracks and the crack propagation.