发动机风扇静子叶片裂纹失效分析

针对发动机风扇静子叶片出现裂纹故障进行失效分析。通过对故障叶片进行外观检查、断口分析、表面形貌检查、截面金相检查、材质分析及断口区域成分分析，并对叶片上缘板排气边转接区域的应力分布进行计算，确定了叶片裂纹性质和产生原因。结果表明:故障风扇静子叶片上缘板转接区域裂纹为高周疲劳性质，导致叶片过早出现疲劳裂纹的主要原因是机匣与上缘板焊接的热影响区进入叶片上缘板排气边转接处的应力集中区；同时叶片工作时受到的振动载荷也加速了疲劳裂纹的产生。并由此提出增加叶片上缘板排气边转接区和焊缝距离的改进建议。

Cracking Analysis of Stator Blade of Aero-engine Fan

The crack of a fan stator blade of aero-engine was analyzed. The crack mode and cause were identified by visual inspection, fracture analysis, surface microscopic inspection, section metallographic examination, material analysis, chemical composition analysis and vibration stress distribution calculation of the corner of exhaust side of edge plate. Results indicate that the crack of fan stator blade edge plate was high-cycle fatigue crack. The welding heat-affected region of casing and edge plate entered into the stress concentration region of the corner of exhaust side of edge plate, which was a critical factor leading to the earlier fatigue cracking. The vibration loading accelerated the fatigue crack. Finally, the improvement proposal was put forward that the distance between the corner of exhaust side and welding should be increased.