K465合金涡轮叶片叶身开裂分析

发动机厂内试车后进行荧光检测，发现多件K465合金涡轮叶片在叶冠叶身出现裂纹。采用体视显微镜和扫描电镜对叶片进行裂纹形貌及断口分析、金相组织检查等。结果表明：裂纹性质为疲劳开裂，起源于内腔表面。裂纹产生原因是叶片采用铝基型芯浇注以及模组方式不当，使得该位置产生较大铸造应力。通过将铝基型芯改为硅基型芯、改进铸造工艺和优化模组方式，可降低叶片的铸造应力，预防此类故障。

Cracking Analysis of K465 Alloy Turbine Blade Body

Several K465 alloy turbine blades were found to have cracks in blade shroud and blade body by fluorescence inspection after test run in factory. Stereomicroscope and scanning electron microscope were used to analyze the crack morphology, crack fracture and metallographic structure of the blade. The results show that the nature of the crack is fatigue cracking, which originates from the surface of the inner cavity. The reason for the crack is that the application of the aluminum-based core casting and the improper module caused higher casting stress in certain position. By changing the aluminum-based core to a silicon-based core, improving the casting process and optimizing the module mode, the casting stress of the blade is reduced to prevent such failures.