金属热处理 ›› 2023, Vol. 48 ›› Issue (5): 184-190.DOI: 10.13251/j.issn.0254-6051.2023.05.028

• 工艺研究 • 上一篇    下一篇

恢复热处理对R26高温合金螺栓组织和力学性能的影响

韩哲文1, 王智春1, 王家健2, 王启冰2, 彭波1, 左月2, 司明宇2, 康举2   

  1. 1.华北电力科学研究院有限责任公司, 北京 100045;
    2.北京石油化工学院 机械工程学院, 北京 102617
  • 收稿日期:2022-11-05 修回日期:2023-03-16 出版日期:2023-05-25 发布日期:2023-06-21
  • 通讯作者: 康 举,副教授,博士,E-mail: kangju@bipt.edu.cn
  • 作者简介:韩哲文(1986—),女,高级工程师,硕士,主要研究方向为电站、电网金属材料的监督检验、故障分析、寿命评估等,E-mail: hanzhewen_23@163.com。
  • 基金资助:
    国家自然科学基金(52175286);先进成形制造教育部重点实验室开放课题(202102);华北电力科学研究院有限责任公司科技项目(KJZ2021024)

Effect of recovery heat treatment on microstructure and mechanical properties of R26 superalloy bolts

Han Zhewen1, Wang Zhichun1, Wang Jiajian2, Wang Qibing2, Peng Bo1, Zuo Yue2, Si Mingyu2, Kang Ju2   

  1. 1. North China Electric Power Research Institute Co., Ltd., Beijing 100045, China;
    2. School of Mechanical Engineering, Beijing Institute of Petrochemical Technology, Beijing 102617, China
  • Received:2022-11-05 Revised:2023-03-16 Online:2023-05-25 Published:2023-06-21

摘要: 对某发电站机组服役约6万小时后硬度超标的R26高温合金螺栓进行恢复热处理,通过化学成分检测、显微组织观察、力学性能测试及断口分析,研究了恢复热处理对R26高温合金螺栓组织和力学性能的影响。结果表明,R26合金的显微组织主要为奥氏体,并存在大量孪晶。硬度超标试样的晶界上存在断续分布的碳化物;经恢复热处理后,晶粒细化且均匀化,晶界上的碳化物溶解,晶内析出γ′相。恢复热处理可使R26合金螺栓的硬度恢复到标准范围内,同时提高塑性和韧性。

关键词: 镍基高温合金, R26合金螺栓, 恢复热处理, 微观结构, 力学性能

Abstract: Recovery heat treatment was carried out for the R26 superalloy bolts which had serviced about 60 000 hours in a power station. The effect of recovery heat treatment on microstructure and mechanical properties of the R26 superalloy bolts was investigated by means of chemical composition analysis, metallographic microstructure observation, mechanical property test and fracture analysis. The results show that the microstructure of the R26 alloy is mainly austenite with a large number of twin crystals. There are discontinuous precipitated carbides along the grain boundaries of the R26 superalloy with abnormal hardness. After recovery heat treatment, the grain is refined and homogenized, and the carbides which locate on the grain boundary are dissolved, moreover, the γ′ phases are precipitated in the grain. The recovery heat treatment can restore the hardness value of the R26 alloy bolts to the standard range, and improve the plasticity and toughness.

Key words: nickel-based superalloy, R26 alloy bolts, recovery heat treatment, microstructure, mechanical properties

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