对电梯主轴在使用过程中发生的断裂进行了失效分析.结果表明:电梯主轴由于热处理工艺不当,使得显微组织中存在上贝氏体和硬度偏低,从而在电梯多次启动和停止过程中,主轴因受到交变载荷而于应力集中最为严重、承载面积最小的键槽转角处发生扭转疲劳断裂.

The cracking reason for the principal axis of an elevator was fatigue fracture according to the failure analysis results.Upper bainite in microstructure and lower hardness decrease the fatigue intensity.The elevator works with high frequency during the process of “start up” and “stop”.So the “R” transition of keyway is the most stress concentration position and the minimal loaded area and thus become the cracking source,which led to the final fatigue fracture and failure of principal axis of the elevator.