金属热处理 ›› 2024, Vol. 49 ›› Issue (5): 17-21.DOI: 10.13251/j.issn.0254-6051.2024.05.003

• 材料研究 • 上一篇    下一篇

高温长期服役S30432钢管的组织与性能

杨希锐1, 江宝世2, 胡锋涛1, 李艳军1, 盛超杰1, 王晨3   

  1. 1.润电能源科学技术有限公司, 河南 郑州 450000;
    2.华润电力菏泽有限公司, 山东 菏泽 274000;
    3.武汉大学 动力与机械学院, 湖北 武汉 430000
  • 收稿日期:2023-11-12 修回日期:2024-03-23 出版日期:2024-05-25 发布日期:2024-06-28
  • 作者简介:杨希锐(1989—),男,工程师,硕士,主要研究方向为电站金属部件的理化检验与组织性能,E-mail:410641621@qq.com。

Microstructure and properties of S30432 steel tube after long-term service at high temperature

Yang Xirui1, Jiang Baoshi2, Hu Fengtao1, Li Yanjun1, Sheng Chaojie1, Wang Chen3   

  1. 1. Rundian Energy Science and Technology Co., Ltd, Zhengzhou Henan 450000, China;
    2. China Resources Power Heze Regional Company, Heze Shandong 274000, China;
    3. School of Power and Machinery, Wuhan University, Wuhan Hubei 430000, China
  • Received:2023-11-12 Revised:2024-03-23 Online:2024-05-25 Published:2024-06-28

摘要: 通过室温拉伸、室温冲击、硬度测试、高温拉伸、金相显微镜、扫描电镜和能谱仪等手段研究了超超临界锅炉服役79 000 h S30432钢管的组织和性能。结果表明,S30432钢管高温服役79 000 h后,室温硬度和抗拉强度升高,塑、韧性均显著降低,断后伸长率已低于标准要求;高温下抗拉强度和塑性显著降低,670 ℃抗拉强度已低于标准外推值;组织严重老化,孪晶消失,除NbC、M23C6等碳化物外,晶内、晶界均不同程度析出了硬脆的σ相,是导致塑、韧性及高温抗拉强度大幅下降的主要原因。

关键词: S30432钢, 高温长时服役, 组织, σ相, 力学性能

Abstract: Microstructure and mechanical properties of the S30432 steel tube after high temperature service for 79 000 h in ultra supercritical units were studied by means of room temperature tensile and impact test, hardness test, high temperature tensile test, metallographic microscope, scanning electron microscope and energy dispersive spectrometer. The results show that the room temperature hardness and tensile strength of the 79 000 h long-term serviced S30432 steel tube increase, while the plasticity and toughness significantly decrease, the elongation is lower than the standard requirement. The tensile strength and plasticity at high temperature significantly decrease, and the tensile strength at 670 ℃ is lower than the standard extrapolation value. The microstructure of the tube material is seriously aged, and the twins disappear. Except for carbides such as NbC and M23C6, σ phases precipitate to varying degrees in the grain or at the grain boundary, which is the main reason for the significant decrease in plasticity, toughness and high temperature tensile strength.

Key words: S30432 steel, high temperature long-term service, microstructure, σ phase, mechanical properties

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