The effect of pneumatic shot peening (PSP) on the fatigue properties of K403 turbine blades has been investigated under the high and low cycle combined fatigue (CCF) load with two types of turbine blades: untreated blades and PSP treated blades. It is found that there is a threshold vibration stress for the blades in this study. The PSP has a positive effect on the CCF life of blades mainly due to the compressive residual stress resulting in the reduction of the number of crack sources and propagation rate, when vibration stresses are below the threshold vibration stress. However, the PSP treatment has no effect or a negative effect when vibration stresses are above the threshold value. The compressive residual stress is released along with the microstructure changes of K403 alloy. Meanwhile, the microstructure changes, reflected in the precipitation of the lamellar MC carbides and σ phases, can accelerate the processes of crack initiation and propagation.

中文翻译：

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气动喷丸处理对K403涡轮叶片高低循环综合疲劳寿命的影响

气动喷丸（PSP）对K403涡轮叶片的疲劳性能的影响已在两种类型的涡轮叶片的高循环和低循环组合疲劳（CCF）载荷下进行了研究：未经处理的叶片和经PSP处理的叶片。发现在该研究中叶片存在阈值振动应力。PSP对叶片的CCF寿命有积极影响，这主要是由于当振动应力低于阈值振动应力时，压缩残余应力导致裂纹源数量和传播速率的减少。但是，当振动应力高于阈值时，PSP处理不会产生任何效果或产生负面影响。压缩残余应力随K403合金的显微组织变化而释放。同时，微观结构发生变化，