概述了气阀弹簧的制造工艺和要点，介绍了因簧丝夹杂物、簧丝表面裂纹、卷簧时表面挤伤、尾端相邻圈之间磨损引发的弹簧断裂案例，通过对案例进行失效分析发现：气阀弹簧发生断裂的主要原因有材料纯净度不高和簧丝表面存在缺陷；簧丝表面缺陷除了来自簧丝本身，也来自制造和装配环节；进行弹簧失效分析时，可采用断口分析和实地调查相结合的方法，力求快速准确地判断原因，以便迅速采取措施避免类似问题的再次发生。

Manufacturing technology and key points of valve spring were summarized. The cases of spring fracture caused by inclusions of spring wire, surface cracks of spring wire, surface extrusion during coiling spring and wear between adjacent rings at the end were introduced. The results of failure analysis showed that the main reason for the fracture of valve spring were the low purity of material and the defects on the surface of spring wire. The surface defects of spring wire came not only from the spring wire itself, but also from the manufacturing and assembly links. When analyzing the failure cases of spring fracture, the method of combining fracture analysis with field investigation could be used to accurately judge the cause, and measures could be taken quickly to avoid the recurrence of fracture problems.