船用柴油机活塞销早期断裂分析

Analysis to premature failure of marine diesel engine piston pin

对某船用柴油机活塞销断裂故障进行了分析研究。金相观察及断口的宏观和微观观察表明,活塞销的破坏属疲劳断裂,疲劳裂纹在表面渗碳层的网状碳化物萌生,进而扩展引发断裂。改进渗碳工艺,杜绝网状碳化物析出是防止活塞销疲劳破断的有效途径。

Premature failure of a marine diesel engine piston pin has been studied. By the metallographic and fracture observation, it is shown that the failure characteristic was considered as fatigue, the cracks initiated on the carbite net of carburizing case, and then propagated to fracture. To inhibit fatigue of piston pin, it is commanded to improve carburizing process and avoid the precipitation of carbide net.