某型发动机在进行300 h长试试车过程中, 材料为FGH4097粉末高温合金的高压涡轮盘发生断裂, 造成发动机烧毁, 对涡轮盘掉块断口进行宏观、微观观察以及能谱分析, 对故障原因进行了排查并对排查结果进行了模拟试验。结果表明: 失效的高压涡轮盘为疲劳断裂, 涡轮盘疲劳断裂的原因是其冷却孔边存在的夹杂物以及夹杂物周围的大面积原始颗粒边界(PPB), 夹杂物主要为电弧焊的焊渣, PPB是焊渣与合金反应生成的伴生物。

An engine was destroyed during long testing of 300 h because of the fracture of the high pressure turbine disk whose material was FGH4097 powder superalloy, the fracture of the disk was analyzed through the macro and micro observation and EDS analysis, and a simulation test was performed on the basis of the analysis results of failure causes. The results show that the fracture of the the turbine disk was fatigue fracture. The causes for the fatigue fracture were the inclusion existing in cooling aperture of the disc and prior particle boundary(PPB) around the inclusion. The inclusion was main arc-welding slag, and the PPB was a concomitant resulted from the reaction of the welding slag and the alloy.