【摘要】 以承温能力达800℃的K439B合金为研究对象，研究该合金标准热处理态组织中γ’相的形态，以及800℃下时效6000、7000、8000和10000 h过程中的γ’相演变规律和粗化行为。结果表明，合金标准热处理后枝晶干γ’相细小均匀，而枝晶间γ’相呈现出大小两种形态。合金在长期时效后枝晶间区域仍然保留双态型γ’相。合金长期时效后γ’相由标准热处理态的球状逐渐向立方状转变，立方状γ’相获得了互相平行的边界，未出现筏排化现象。合金在长期时效过程中，γ’相尺寸增大，但体积分数变化不明显。γ’相尺寸随时效时长的变化同时符合Lifshitz-Slyozov-Wagner(LSW)和相界面扩散控制理论（TIDC）两种模型，其内在原因认为是由于元素在基体与界面的扩散速率相当。更多还原

【Abstract】 This article took K439B alloy with a temperature bearing capacity of 800 ℃ as the research object to study the γ’ phase morphology in the standard heat-treated condition,and the γ’ phase evolution and coarsening behavior during aging at 800 ℃ for 6000,7000,8000,and 10 000 h.The results indicate that the γ’ phase at the dendrites in the alloy is fine and uniform,while the γ’ phase between the dendrites presents two types.After long-term aging,the bimodal γ’ phase is still retained in the interdendritic region,and the γ’ phase transforms from spherical to cubic shape without any rafting phenomenon.During the long-term aging process,the γ’ phase size of the K439B increases,but the change in volume fraction is not significant.The variation of γ’ phase size with aging time conforms to both Lifshitz-Slyozov-Wagner(LSW) and theory of interface diffusion control(TIDC) models.The internal reason is believed to be the equivalent diffusion rate of elements between the matrix and interface.更多还原