摘要
某公司生产的猎枪在进行空枪射击试验时,部分击针发生了断裂。笔者采用化学成分分析、金相检验、扫描电镜观察等方法对断裂形成原因进行分析。试验结果表明,击针断裂的机制为疲劳断裂,击针的化学成分和基体金相组织正常。但击针表面有脱碳层导致击针表面弱化,使得击针表面硬度和强度明显低于基体,加速了疲劳源的形成,且击针承受较大交变应力的作用,加速了疲劳源的扩展。综合分析认为:击针断裂属于表面产生脱碳层导致的早期疲劳断裂。
During empty gun firing experiment of shotgun produced by a company, fracture of some firing pins occurred. Chemical analysis, metallography, scanning electron microscopy and other methods were carried out to analyze the reasons for the formation of fracture. The experimental results show that the fracture mech- anism of firing pins is fatigue fracture, chemical composition and mierostructure of firing pin are normal. But the surface decarburization of firing pin led firing pin surface weakened, making surface hardness and strength of firing pin significantly lower than the base, aeeelerating the formation of fatigue source. The firing pins withstand greater alternating stress, which accelerated fatigue source extensions. Comprehensive analysis indi- cated that the firing pin breakage is due to the carbon layer which causes early fatigue fracture.
出处
《物理测试》
CAS
2014年第1期43-45,共3页
Physics Examination and Testing
关键词
击针
脱碳
疲劳
firing pin
decarbonization
fatigue
