电梯钢丝绳疲劳断裂原因分析

对电梯钢丝绳断丝进行了表面形貌、显微组织、化学成分等检测分析。结果表明:电梯钢丝绳表面断丝为疲劳断裂,主要原因是钢丝绳在循环应力的作用下,受到外部挤压以及长期摩擦失油处形成疲劳应力集中点,萌生疲劳裂纹。又因钢丝绳表面挤压处产生白色马氏体,使得钢丝表面韧性弱化,加速了疲劳裂纹源的形成,故而出现了早期钢丝绳表面钢丝断裂;最后提出了相应的改进措施。

Cause Analysis on Fatigue Fracture of Elevator Wire Rope

The surface morphology,microstructure and chemical composition of broken wire of the elevator wire rope were detected and analyzed. Results showed that the fatigue failure was the main reason for the wire breaking on the surface of the elevator wire rope. When the cyclic stress was applied,the fatigue stress concentration point of the wire rope formed and the fatigue cracks emerged under the action of external friction and long term friction. Besides,the generated white martensite on the surface of the wire rope weakened the toughness of the steel wire,which accelerated the formation of the fatigue crack source. Therefore,the wire fracture on the surface of the wire rope appeared at the earlier period. Finally,the corresponding countermeasures were also proposed.