CAJ | 학술논문

通过蠕变性能测试及组织形貌观察，结合元素扩散迁移率计算，研究DZ125合金在1040℃蠕变期间的组织演化规律。结果表明：高温蠕变期间，合金在枝晶间/干区域发生不均匀的组织演化，枝晶间区域形成的筏状γ′相尺寸粗大，而枝晶干区域γ′相沿(001)晶面形成细小的 N-型筛网状筏形结构，且γ基体相连续充填在筛网状γ′相之间，可保证合金的高塑性。在1040℃、137 MPa蠕变期间，合金枝晶干区域的γ′相经3 h转变成筏状结构，随施加应力的降低，γ′相发生筏形化转变的时间延长；其中，Al、Ta具有较高扩散迁移率是促使合金发生较快筏形化转变的主要原因。
통과연변성능측시급조직형모관찰，결합원소확산천이솔계산，연구DZ125합금재1040℃연변기간적조직연화규률。결과표명：고온연변기간，합금재지정간/간구역발생불균균적조직연화，지정간구역형성적벌상γ′상척촌조대，이지정간구역γ′상연(001)정면형성세소적 N-형사망상벌형결구，차γ기체상련속충전재사망상γ′상지간，가보증합금적고소성。재1040℃、137 MPa연변기간，합금지정간구역적γ′상경3 h전변성벌상결구，수시가응력적강저，γ′상발생벌형화전변적시간연장；기중，Al、Ta구유교고확산천이솔시촉사합금발생교쾌벌형화전변적주요원인。
By means of creep-curve measurements and microstructure observations, combined with the calculation of element-diffusion mobility, the microstructure-evolution regularity of DZ125 nickel-based superalloy during creep at 1 040 ℃ was investigated. The results show that, during high-temperature creep, inhomogeneous microstructure evolution occurs in the interdendrite and dendrite arm regions. The coarser rafted γ′ phase appears in the interdendrite regions, the fine raftedγ′phase with the mesh-like N-type structure on (001) plane forms in the dendrite arm regions, and the γ matrix phase fills continuously between the mesh-like rafted γ′ phase to ensure the better plasticity of the alloy. During creep at (1 040 ℃, 137 MPa), the cuboidalγ′phase in the dendrite arm region transforms into the rafted structure after being crept for 3 h. As the applied stress decreases, the rafted time of γ′ phase prolongs. Thereinto, the bigger diffusion mobilities of elements Al and Ta are the main reason for the alloy occurring rapidly microstructure evolution.