港口用钢丝绳断裂失效分析

Break Failure Analysis of Wire Rope for Port

对6×19W+FC—28.5港口用钢丝绳失效原因进行分析,通过拆股检测,发现相邻股的相互挤压相当严重,在股相互接触的钢丝表面上出现严重的双坑状压痕。对钢丝断口形貌及钢丝组织进行电子金相扫描观察,并对影响钢丝绳失效的因素进行剖析,结果表明:较深的双坑状压痕对钢丝表面裂纹的萌生和早期疲劳断裂影响极大,钢丝在弯曲疲劳应力反复作用下,其表面多处萌生裂纹,逐渐形成多疲劳源,然后向内扩展,直至过载断裂。钢丝绳出现早期疲劳断丝而报废与其显微组织不均匀性和强度塑性匹配较差有关。

To analyze the failure cause of 6 × 19W ＋ FC - 28.5 wire rope for port. It is discovered by strands dismantling checking and measure that the extrusion each other of border upon strands is grave, the grave double pit type impress appears on the contacting steel wires surface of strands. The fracture profile and microstructure of wire are observed with SEM, and the factors affecting wire rope failure are analyzed. The results show that deeper double pit type impress greatly affects the burgeoning of surface crackle and the early fatigue fracture, wires are operated by bend fatigue stress again and again, crackles surgeon at many places on the wire surface, forming many fatigue sources gradually, then expand to inner up to fracture due to overload. Discarding as useless of wire rope due to early fatigue wire breaking is relative to uneven microstructure and bad match between strength and plasticity.