摘要
一根用来紧固节段式水泵的穿缸螺栓仅服役3个月便产生断裂。采用断口分析、金相检验和硬度测定等方法,对断裂螺栓进行了分析。分析结果表明,断口宏观上有明显的贝纹线花样,微观形态主要为疲劳辉纹,因此螺栓的断裂是疲劳断裂。材料棒中存在严重的中心碳偏析致使材料强度不均匀,造成材料强度偏低。碳偏析及材料强度不足是引起断裂的主要原因。
The fracture reasons of fastening bolts are analyzed using fractography, metallographic analysis and hardness testing in this paper. It is shown that the fracture surface characterized with cowrie pattern lines and the microstructure being fatigue striation, which indicated the fracture of the bolt is brittle. Metallographic analysis shows that the central carbon segregation was existed heavily in the raw material. It is also found that the strength of the material is lower than standard. Therefore, such fatigue fracture mainly due to the existing of central carbon segregation.
出处
《理化检验（物理分册）》
CAS
2003年第10期532-534,共3页
Physical Testing and Chemical Analysis(Part A:Physical Testing)
