风电机组齿轮箱行星轮失效分析研究

Failure Analysis and Research on the Planet Gear of Wind Turbine Gearbox

摘要: 针对风电机组齿轮箱内的行星齿轮失效断齿，通过宏观形貌、化学成分分析、金相组织观察、断口扫描电镜分析、力学性能测试对失效行星轮进行分析。结果表明：行星齿轮组织内部存在大量尺寸超标夹杂物与高含碳量第二相质点，结合外加载荷作用，造成行星轮首先于齿根处开裂失效。据此，提出了金属钢件熔炼过程中优化熔炼工艺，热处理过程中采用均匀加热方式或热处理后进行二次回火与均匀化退火工艺。

Abstract: The study focuses on the planet gear failure analysis of a wind turbine gearbox. The failed planet gear was examined through macroscopic observation, chemical composition analysis, metallographic examination, fracture surface scanning electron microscopy (SEM), and mechanical property testing. The results indicated that a large number of oversized inclusions and carbon-rich second-phase particles existed within the microstructure of the planet gear. Under the combined influence of these material defects and external service loads, the planet gear initiated a fatigue crack at the tooth root, which subsequently propagated and led to the final fracture of the gear. Based on this, improvement measures are proposed for the steel manufacturing process, including optimizing the melting temperature and holding time during the smelting stage, and adopting uniform heating methods during heat treatment, followed by tempering or homogenization annealing to improve microstructural uniformity and reduce the risk of similar failures.