发动机活塞开裂分析  

Analysis on Cracking of Engine Piston

作　　者：张小荣[1] 陈培磊[1] 姜起东[1] 

机构地区：[1]奇瑞汽车股份有限公司试验和整车技术工程院,芜湖241009

出　　处：《理化检验（物理分册）》2013年第5期330-333,共4页Physical Testing and Chemical Analysis(Part A:Physical Testing)

摘　　要：某型发动机在台架试验中活塞顶部出现开裂,裙部磨损。对开裂活塞的断口、化学成分、显微组织和硬度等进行了分析,结果表明:活塞顶部的开裂为疲劳开裂;发动机工作过程中冷却不良,活塞顶面温度过高,引发了热疲劳裂纹的产生,在交变燃气爆发高压应力的作用下,裂纹不断扩展,最终导致活塞的开裂。During the bench test of a certain type of engine, cracking on the top surface of piston and wearing in the position of skirt were found. The fracture, chemical composition, microstructure, hardness and so on were analyzed, the results showed that the fatigue cracking appeared on the top surface of piston; the thermal fatigue cracks was caused by insufficient cooling in working and high temperature of the top surface of piston, the cracks extended under high pressure stress of alternating gas, and led to cracking of the piston at last.

关 键 词：发动机 活塞 冷却不良 疲劳开裂 热疲劳裂纹 机械载荷 

分 类 号：TK413.33[动力工程及工程热物理—动力机械及工程]