机车280型柴油机连杆衬套在使用过程中发生开裂,采用宏观观察、扫描电镜分析、组装工艺分析、受力分析以及金相检验等方法对开裂的连杆衬套进行了综合分析。结果表明,连杆衬套的装配工艺不合理,造成衬套与活塞销高点接触而产生应力集中,这是导致连杆衬套开裂的原因。定位销位置设计不合理以及衬套基体存在严重的疏松,是促使连杆衬套开裂的主要因素。

The wrist-pin took place cracking during usage. The methods of macrostructure,SEM,assembly technology analysis,force analysis and metallographic examination were used to analyze the cracked connecting rod bushes. The results showed that the assembly technology of connecting rod bushes was unreasonable,the unreasonable technology caused high point contact between bearing and pin and produce stress concentration,this was fatal reason to cause connecting rod bushes cracking. The irrational location of locating stud and heavy porosity existing in bearing was important reason to promote connecting rod bushes cracking. Suggestions were put forward.