摘要
通过蠕变试验,研究了晶粒尺寸对GH4169合金蠕变性能的影响。结果表明,随着晶粒尺寸的增加,材料蠕变寿命显著增加。分析表明:细晶和粗晶材料的蠕变机理不同,细晶材料蠕变过程由基体内的位错攀移所控制,表现为穿晶的塑性断裂特征;粗晶材料蠕变过程由位错在基体中滑移和第二相颗粒强化所控制,表现为沿晶的脆性断裂。另外,晶粒长大,晶界面积进一步减少,蠕变断裂沿晶扩展的通道减少,蠕变沿晶裂纹扩展速率降低,也是粗晶材料蠕变寿命提高的重要原因。
Through the creep test,the effect of grain size on the creep properties of GH4169 alloy was discussed.The results show that the creep life becomes increased significantly with the growth of grain size;the creep mechanisms of fine-grained and coarse-grained materials are different,i.e.the dislocation climb within the matrix controls the creep process of fine-grained materials and a transgranular plastic fracture characterizes it;both the sliding of dislocations in the matrix and the second-phase particles strength controls the creep process of coarse-grained materials and the brittle fracture along the grain characterizes it.In addition,with the growth of grains,the grain boundary area further decreases,including the reduction of channels for creep fracture propagation along the grain and the growth rate of creep intergranular crack decreases,these are important reasons that the creep life of coarse-grained materials can be promoted.
作者
姜千
姜勇
巩建鸣
JIANG Qian;JIANG Yong;GONG Jian-ming(School of Mechanical and Power Engineering,Nanjing Tech University)
出处
《化工机械》
2025年第6期917-923,952,共8页
Chemical Engineering & Machinery
基金
国家重点研发计划项目(批准号:2022YFF0605600)资助的课题。
