利用直读光谱仪、洛氏硬度计、金相显微镜、扫描电子显微镜等试验手段对50CrVA弹簧钢的断裂失效原因进行分析。结果表明：失效弹簧的工作介质中含有H₂S，同时设备的安装位置靠近海边，易形成湿H₂S环境，长期服役后，弹簧表面涂层发生失效，使弹簧钢基体暴露在湿H₂S环境中，加之弹簧显微组织为脆性较大的马氏体，在湿H₂S腐蚀环境和较高的剪切应力作用下，弹簧发生了沿晶应力腐蚀开裂，最终导致其断裂失效。

The fracture failure causes of 50CrVA spring steel were analyzed by means of direct reading spectrometer, Rockwell hardness tester, metallographic microscopy and scanning electron microscopy. The results showed that the working medium of the failed spring contained H₂S, and the installation position of the equipment was close to sea, so it was easy to form wet H₂S environment. The coating on the spring surface failed after long-term service, exposing the spring steel substrate to the wet H₂S environment. Under the action of wet H₂S corrosion environment and high shear stress, coupled with the brittle martensite microstructure of the spring, the intergranular stress corrosion cracking occurred, which eventually leaded to fracture failure.