某风电机组主轴断裂原因分析

Cause analysis of main shaft fracture of a wind turbine

针对某风电机组激光修复主轴出现断裂的现象,对样品进行了宏观检查、化学成分分析、室温拉伸试验、冲击试验、脆性转变温度试验、金相分析、熔覆层厚度测量、硬度试验和断口扫描电镜分析。结果表明:主轴样品基体材质和熔覆质量不合格,样品的断裂性质属于多源区的高周疲劳断裂,这些源区均位于紧邻熔覆层的热影响区外壁;引起主轴发生高周疲劳断裂的主要原因是激光熔敷过程中引起的熔覆热影响区性能较差。

In view of the fracture of laser repaired main shaft of a wind turbine, several tests and analysis methods were carried out for the samples, such as macro inspection, chemical composition analysis, room temperature tensile test, room temperature impact test, brittle transition temperature test, metallographic analysis, cladding size measurement, hardness test and fracture scanning electron microscope analysis. The results show that, the matrix material and deposition quality of the shaft sample were unqualified, and the fracture property of the sample was high cycle fatigue fracture in multi-source areas. These source areas located on the outer wall of the heat affected zone adjacent to the cladding layer. The main cause of the shaft fatigue fracture was the poor performance of the cladding heat affected zone.