钢丝绳钢芯早期断裂失效分析

用户在使用搁置3 a的钢芯钢丝绳时,由于钢芯首先断裂,导致用后不久发生断股事故。经检验,钢芯的断裂为疲劳断裂,疲劳断裂的原因是由于钢丝绳生产工艺控制不严以及服役过程中受到弯曲振动载荷,使芯丝表面磨损和硬化,并在磨损面上出现纵横向裂纹和蚀坑,成为疲劳源,裂纹扩展导致芯丝过载断裂,直至钢芯断裂,从而导致绳股破断。钢丝绳因其钢芯过早断裂而报废,与钢丝绳芯丝抗拉强度波动、表面缺陷以及钢芯疲劳寿命与其钢丝绳疲劳寿命匹配较差有关。

Early break failure analysis of steel core for steel wire rope

Because steel core fractured firstly, some strands of steel core wire rope which was laid up 3 years breaked after a short time with load. The inspection and analysis show that the break of steel core was fatigue fracture. The cause are as follows： the wire rope production process is not strictly controlled, flexural vibration load is suffered when the wire rope is in service, the surface of core wire is worn and hardened, some transversed and longitudinal cracks and etching pit present on the wire surface, which become cracks origin, the development of cracks causes core wire break after overloaded, and finally the steel core breaks, which causes wire rope and strand break. The fact that for the wire core fractures early wire rope is discarded has the following relationship such as the tensile strength of its core wire fluctuates, its surface defect and the poor match between steel core fatigue life and wire rope fatigue life.