某发动机动力涡轮导向器裂纹原因分析

Cracks Analysis of Power Turbine Stator in an Engine

针对某型发动机使用后发现的动力涡轮导向器叶片裂纹及掉块现象,通过对裂纹件及样机件进行冶金对比分析和模拟验证试验,确定导致零件产生裂纹和掉块的主要原因是零件内部存在柱状晶粒。发动机工作过程中,在冷热循环应力和结构约束应力的共同作用下引发的热疲劳开裂。对此提出了优化铸造工艺消除柱状晶的措施,有效地改善了零件裂纹和掉块现象。

Crack and stripping was found on motive power turbine guide apparatus blade used in an engine. Metallurgy contrast analysis and simulation test between the failed and prototype blade were carried out. The result showed that there was columnar crystalline grain in the blade. When the engine was working, the blade appeared heat-fatigue crack under cold-heat circulate stress and constraining force. A optimal casting technique for eliminating the columnar crystalline was proposed to effectively improve the phenomenon with the crack and stripping of the component.