In the present study, both the as‐received and the 600‐h‐serviced turbine blades were tested under the creep‐fatigue loading. The results showed that the service‐exposed blades exhibited a longer creep‐fatigue life than the as‐received ones due to the refinement of grain size and the increasing of hardness during the service process. Micro structural characterization revealed that there was no directional coarsening or rafting of γ′ precipitate after 600 h of service. Moreover, the as‐received blades exhibited initial cyclic hardening followed by saturation and softening, whereas the 600‐h‐serviced blades only exhibited continuous softening until fracture. A conservative service life prediction approach was proposed considering the experienced mission profile. This service life estimation method provides a new way to assess the durability of turbine blade.

中文翻译：

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接收和使用中的涡轮叶片蠕变疲劳行为的实验研究：机理和寿命评估

在本研究中，在蠕变疲劳载荷下对接收的和600小时维修过的涡轮叶片进行了测试。结果表明，由于服役过程中晶粒尺寸的细化和硬度的增加，在役服役的叶片比在役叶片具有更长的蠕变疲劳寿命。微观结构表征表明，服役600小时后，γ'沉淀没有定向变粗或浮出。此外，收到的叶片先表现出周期性的循环硬化，然后达到饱和和软化，而600小时维修的叶片只表现出持续的软化直至断裂。考虑到经验丰富的任务概况，提出了一种保守的使用寿命预测方法。