Cr12Mo1V1钢电连接压接模具失效的试验与仿真

Experiment and simulation on failure for Cr12Mo1V1 steel electric connection crimping mold

针对某型Cr12Mo1V1钢电连接压接模具在服役200次后发生脆性断裂的现象,采用5M1E的失效分析方法,结合Cr12Mo1V1冷作模具钢特性,采用扫描电镜、直读光谱仪、洛氏硬度计、金相显微镜等对Cr12Mo1V1钢电连接压接模具的宏观断口形貌、材料成分、力学性能和显微组织进行分析检测,并借助Deform软件对电连接压接模具的压接过程进行仿真模拟。结果表明:电连接压接模具的材料成分不达标、强度过低以及内部共晶碳化物不均匀、碳化物尺寸超标是导致模具短寿命和脆性断裂的根本原因。此外,模具止裂槽、圆孔位置等分布不合理,导致模具在挤压过程中出现应力集中,是模具发生脆性断裂失效的主要原因。最后,从模具原材料、热处理、锻造工艺以及模具结构设计等方面提出了电连接压接模具的延寿措施。

For the brittle fracture phenomenon of a certain type of Cr12Mo1V1 steel electric connection crimping mold after 200 times of service,the macro fracture morphology,material composition,mechanical properties and microstructure of Cr12Mo1V1 steel electric connection crimping mold were analyzed and detected by 5M1E failure analysis method,combining with the characteristics of cold working die steel Cr12Mo1V1 and using scanning electron microscopy,direct reading spectrometer,Rockwell hardness tester,metallographic microscope and other means,and the crimping process of the electric connection crimping mold was simulated by software Deform.The results show that the substandard material composition,low strength,uneven internal eutectic carbides and excessive carbide size of the electric connection crimping mold are the fundamental reasons for the short service life and brittle fracture of the mold.In addition,the unreasonable distribution of crack stop grooves and circular hole positions of the mold lead to stress concentration during the extrusion process,which is the main reason for brittle fracture failure of the mold.Finally,the life extension measures of electric connection crimping mold are put forward from the aspects of mold raw materials,heat treatment,forging process and mold structure design.