化工机械设备地脚螺栓断裂失效分析

某化工设备地脚螺栓在运行过程中发生断裂,通过对断裂螺栓采用化学成分分析、断口形貌分析、金相组织分析、扫描电镜、显微硬度分析等方法分析了其断裂原因。一系列分析表明,正常断裂与异常断裂螺栓在化学成分、显微硬度、金相组织等方面没有明显差异,说明这些均不是造成螺栓异常断裂的主要原因;正常断裂与异常断裂微观断口形貌分析结果表明,螺栓芯部出现偏聚现象,螺栓在调质高温回火的过程中,发生偏聚继而导致了疲劳裂纹的萌生及扩展,最终引发螺栓断裂。

Fracture Failure Analysis of Foundation Bolt Used in Chemical Engineering Machinery

Foundation bolt of chemical engineering machinery was found broken in the running. The fracture reasons were analyzed by chemical composition analysis, fracture morphology analysis, metallographic structure analysis, micro-hardness analysis on normal fracture bolts and abnormal fracture bolts. The series of analysis results showed that, there is no obvious difference in chemical composition, micro-hardness, metallographic structure between normal fracture and abnormal fracture bolts, these aspects are not the reasons for abnormal fracture of bolts. Fracture morphology analysis of both normal and abnormal fracture bolts showed that segregation was found in the process of hardening and tempering, which leads to fatigue crack initiation and growth, and finally causes screw fracture.