某高功率柴油机活塞失效分析及解决方案

Analysis and Solution on Fracture Failure of the Piston Used in a High Power Diesel Engine

针对某高功率柴油发动机铸造铝合金活塞在冷热冲击台架试验后出现顶部开裂现象,综合了活塞及对手件尺寸检测、涡流探伤检测、金相检测及电镜检测的结果,经分析判定为铸造工艺中铝合金氧化皮夹杂是此次活塞出现开裂失效的根本原因。根据分析结果,针对活塞开裂情况提出了对手件设计方案及活塞铸造工艺优化方案并对优化后的活塞进行了三轮冷热冲击台架试验+800小时耐久台架试验,均未再出现活塞开裂现象,可判断为改良方案有效。

A cast aluminum alloy piston of high power diesel engine cracked in thermal shock test。It is concluded that the mixed oxide scale of aluminum alloy in the casting process is the root cause of the piston cracking failure through size inspection,eddy current flaw detection,metallographic examination and electron microscope examination。The piston passed thermal shock test after optimizing the casting process。It can be judged that the improved scheme is effective.