【摘要】 经过两种不同热处理的Inconel 718合金在650℃下进行了低周疲劳试验。两种材料显微组织的差別仅在于γ″析出相尺寸不同。实验结果表明,具有大γ″相粒子材料疲劳寿命较长。γ″相大小对疲劳断口形态也有影响,小γ″相材料的疲劳条纹比较均匀、连续,而且条纹间的二次裂纹较少。这种现象与位错切割γ″粒子的难易程度有关。更多还原

【Abstract】 Low cycle fatigue tests of two heat treated IN 718 Alloy were carried out at 650℃. The only difference of the microstructure was the size of γ’ precipitates. The results show that the fatigue life increases with the bigger size of γ″ precipitates. The size of γ″ precipitates also effects the fatigue fracture morphology. The alloy with small size of γ″ precipitates exhibits more uniform and continuous striations, and less secondary cracks. This phenomenon should be attributed to difficult or easy of γ″ precipitates sheared by dislocations.更多还原