金属热处理 ›› 2026, Vol. 51 ›› Issue (2): 23-32.DOI: 10.13251/j.issn.0254-6051.2026.02.004

• 组织与性能 • 上一篇    下一篇

热暴露对IN939高温合金组织与性能的影响

赵亮1,2,3, 王琳琳1, 王平1, 王旻2,3, 马颖澈2,3   

  1. 1.东北大学 材料科学与工程学院, 辽宁 沈阳 110819;
    2.中国科学院金属研究所 师昌绪先进材料创新中心, 辽宁 沈阳 110016;
    3.中国科学院金属研究所 中国科学院核用材料与安全评价重点实验室, 辽宁 沈阳 110016
  • 收稿日期:2025-09-13 修回日期:2025-12-28 发布日期:2026-03-05
  • 通讯作者: 王 旻,副研究员,博士,E-mail:minwang@imr.ac.cn
  • 作者简介:赵 亮(1998—),男,硕士研究生,主要研究方向为镍基高温合金组织与性能,E-mail:zhli8899@163.com。

Effect of thermal exposure on microstructure and properties of IN939 superalloy

Zhao Liang1,2,3, Wang Linlin1, Wang Ping1, Wang Min2,3, Ma Yingche2,3   

  1. 1. School of Materials Science and Engineering, Northeastern University, Shenyang Liaoning 110819, China;
    2. Shi-chang Xu Innovation Center for Advanced Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang Liaoning 110016, China;
    3. Key Laboratory of Nuclear Materials and Safety Evaluation, Institute of Metal, Chinese Academy of Sciences, Shenyang Liaoning 110016, China
  • Received:2025-09-13 Revised:2025-12-28 Published:2026-03-05

摘要: 研究了IN939镍基铸造高温合金在800 ℃热暴露最长至1000 h过程中的组织演变及其对800 ℃拉伸性能的影响,分析了合金的变形机制和断裂形式。结果表明,随着热暴露时间的增加,γ′相逐渐粗化,形貌保持球状不变,γ′相的长大符合LSW理论,粗化速率为172.9 nm3/h。M23C6碳化物发生长大,MC碳化物未发生明显退化,合金未析出TCP等有害相。随热暴露时间的延长,合金抗拉强度和屈服强度下降,伸长率和断面收缩率整体呈上升趋势。在热暴露过程中800 ℃拉伸屈服阶段的主要变形机制为Orowan绕过机制,γ′相的长大,使得基体通道宽化,位错运动容易,导致合金软化,塑性提高。热处理态和热暴露后断裂形式均为MC碳化物破碎导致孔洞、微裂纹的萌生与扩展,使得合金发生穿晶断裂。

关键词: 高温合金, 热暴露, 组织演变, 高温拉伸性能

Abstract: Microstructure evolution of the IN939 nickel-based cast superalloy after thermal exposure at 800 ℃ for up to 1000 h and its effect on tensile properties at 800 ℃ were investigated, the deformation mechanism and fracture form of the alloy were analyzed. The results show that, the γ′ phase coarsens gradually with the increase of thermal exposure time, the morphology of the γ′ phase remains spherical, the growth of γ′ phase is consistent with Lifshitz-Slyozov-Wagner (LSW) theory, and the roughening rate is 172.9 nm3/h. M23C6 carbides grow up, MC carbides do not degenerate significantly, and the alloy does not precipitate TCP and other harmful phases. With the extension of thermal exposure time, the tensile strength and yield strength of the alloy decrease, while the elongation and the percentage reduction of area of the alloy increase. The Orowan bypass mechanism is the main deformation mechanism in the tensile yield stage at 800 ℃ during thermal exposure. The growth of γ′ phase widens the matrix channel, dislocation movement is easy, resulting in softening of the alloy and increased plasticity. The fracture modes in both the heat-treated state and after thermal exposure are due to the initiation and propagation of voids and microcracks caused by the fragmentation of MC carbides, leading to transgranular fracture of the alloy.

Key words: superalloy, thermal exposure, microstructure evolution, high-temperature tensile properties

中图分类号: