Experimental and microstructural analyses were used to calibrate a MultiStage Fatigue model that included the number of cycles for incubation, microstructurally small crack growth, and long crack growth of 304L stainless steel. Fully reversed cyclic loading tests at strains of 0.3%, 0.5%, and 1.0% were used to characterize the material performance of 304L stainless steel. To assess the microstructural characteristics of 304L stainless steel, the fatigued fracture surfaces were examined with scanning electron microscopy for particles and crack initiation sites, while phases, grain sizes, and grain orientations were investigated using electron backscatter diffraction. Results from both the experimental data and microstructural analysis were then incorporated into the MultiStage Fatigue model to quantify the incubation, small crack regimes, and the total fatigue life of 304L stainless steel. The Multistage Fatigue model captured the fatigue behavior of 304L stainless steel by predicting that fatigue life would be dominated by incubation below 0.5% strain amplitude and by crack growth above 0.5% strain amplitude.

实验和微观结构分析用于校准多阶段疲劳模型，该模型包括 304L 不锈钢的孵化周期数、微观结构小裂纹扩展和长裂纹扩展。应变为 0.3%、0.5% 和 1.0% 的完全反向循环加载试验用于表征 304L 不锈钢的材料性能。为了评估 304L 不锈钢的微观结构特征，使用扫描电子显微镜检查疲劳断口表面的颗粒和裂纹萌生位置，同时使用电子背散射衍射研究相、晶粒尺寸和晶粒取向。然后将实验数据和微观结构分析的结果合并到 MultiStage Fatigue 模型中，以量化孵化、小裂纹状况、和 304L 不锈钢的总疲劳寿命。多阶段疲劳模型通过预测疲劳寿命将由低于 0.5% 应变幅度的孵化和高于 0.5% 应变幅度的裂纹扩展主导，从而捕获了 304L 不锈钢的疲劳行为。