柴油发动机铝气缸盖喷油器孔开裂分析

Cracking Analysis of Fuel Injector Holes in Aluminum Cylinder Head of Diesel Engine

通过宏观形貌观察、显微组织检验、金相分析、化学成分分析、硬度与力学性能检测等方法对柴油发动机铝气缸盖喷油器孔进行综合试验,以分析铝气缸盖喷油器孔开裂的原因。结果表明,裂纹起源于气缸盖第二缸喷油器孔底部对应排气侧的水道壁,以疲劳裂纹的方式扩展,直至贯穿喷油器孔壁。

The cracking reason of aluminum cylinder head injector hole was analyzed by comprehensive test of aluminum cylinder head injector hole by means of morphology observation,chemical composition analysis,microstructure examination,hardness and mechanical property test,etc.The result shows that the crack originated from the channel wall at the bottom of the nozzle hole of the second cylinder of the cylinder head corresponding to the exhaust side,and is propagated as a fatigue crack until the nozzle hole wall is penetrated.