摘要
ML30CrMnSi螺钉在装配时出现断裂。采用断口宏观形貌观察和扫描电镜观察、金相组织检查、硬度及氢含量测定等方法分析螺钉断裂的原因,并确定螺钉的断裂性质为脆性断裂。脆性断裂原因:螺钉头部的十字槽冷镦成形过程中操作不当,导致十字槽底部产生裂纹,在酸洗、镀锌等工艺过程中,由于氢沿裂纹渗入基体,在外力作用下故障件容易发生脆性断裂。螺栓材料中微裂纹、应力集中和其他缺陷的存在,是加速氢的聚集、扩散乃至断裂的必要条件,从而导致螺钉在装配过程中出现断裂。
ML30CrMnSi screws appeared fracture in the process of assembly. The reason of screw fracture was analyzed by using the methods such as macro morphology and SEM observation,microstructure inspection,hardness and hydrogen content test,and the fracture of screw was determined to be brittle fracture. The reasons of brittle fracture are as follows： improper operation in the process of cold heading forming of screw head cross recess,cracks occur in the bottom of cross recess,in the process of acid pickling and galvanizing,hydrogen infiltrates into matrix along crack,existence of microcracks,stress concentration and other defects are the necessary condition to accelerate the aggregation and diffusion of hydrogen and fracture,the result causes screw fracture in the process of assembly process.
出处
《金属制品》
2015年第3期54-58,共5页
Metal Products
