Fatigue tests conducted on various types of materials often exhibit significant scatter, particularly in High Cycle Fatigue tests, attributed to imperfections located at the scale of the microstructure. In metallic materials, one contributor to this dispersion, but not the only one, is the variation in grain size, which cannot be uniform in a structure that has undergone a complex thermal history during its manufacturing process. This paper introduces a new model for predicting the evolution of the grain size in the nickel-based superalloy Inconel® 718 based on the applied thermal load and explores its impact on cyclic elasto-viscoplastic behaviour and fatigue life predictions. The proposed approach is applied to a complete numerical life analysis of an aircraft turbine disk.

中文翻译：

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Inconel 718 高温合金非线性行为和疲劳损伤的晶粒尺寸敏感建模


对各种类型的材料进行的疲劳测试通常会表现出明显的分散性，特别是在高周疲劳测试中，这归因于微观结构尺度上的缺陷。在金属材料中，造成这种分散的一个因素（但不是唯一因素）是晶粒尺寸的变化，在制造过程中经历了复杂热历史的结构中，晶粒尺寸不可能是均匀的。本文介绍了一种基于所施加的热载荷来预测镍基高温合金 Inconel® 718 晶粒尺寸演变的新模型，并探讨了其对循环弹粘塑性行为和疲劳寿命预测的影响。所提出的方法应用于飞机涡轮盘的完整数值寿命分析。