金属热处理 ›› 2021, Vol. 46 ›› Issue (12): 209-213.DOI: 10.13251/j.issn.0254-6051.2021.12.034

• 组织与性能 • 上一篇    下一篇

低硬度P91钢管长时服役后的组织性能和安全性评价

邓辉   

  1. 中国大唐集团科学技术研究院有限公司 中南电力试验研究院, 河南 郑州 450000
  • 收稿日期:2021-07-05 出版日期:2021-12-25 发布日期:2022-02-18
  • 作者简介:邓 辉(1991—),男,工程师,硕士,主要研究方向为理化检验与失效分析,E-mail:353838627@qq.com

Microstructure, properties and safety evaluation of low hardness P91 steel tube after long service

Deng Hui   

  1. Central South Electric Power Test Research Institute, China Datang Corporation Science and Technology Research Institute, Zhengzhou Henan 450000, China
  • Received:2021-07-05 Online:2021-12-25 Published:2022-02-18

摘要: 通过显微组织观察和能谱分析、室温拉伸试验、室温冲击试验、高温短时拉伸试验、高温持久性能试验研究了低硬度P91钢管服役105 h后的组织和性能,并进行安全性评价。结果表明:长时服役硬度为157 HBW的低硬度P91钢管组织为块状铁素体和大尺寸析出相M23C6,与正常硬度管相比,其常温力学性能和高温短时力学性能大幅降低,105 h持久强度外推值低于标准推荐值36%,通过评估得出该机组高压导汽管低硬度直管段剩余寿命为54 075 h,机组运行存在较大安全隐患。

关键词: P91钢管, 长时服役, 低硬度, 高温持久强度, M23C6

Abstract: Microstructure, properties and safety evaluation of low hardness P91 steel after 105 h service were studied by means of microstructure observation, energy dispersive spectrum (EDS) analysis, room temperature and high temperature mechanical property test, room temperature impact test and high temperature stress rupture test. The results show that the microstructure of low hardness P91 steel tube (157 HBW) after long service is composed of massive ferrite and large size M23C6 phase. Compared with the normal hardness tube, its mechanical properties at room temperature and short time mechanical properties at high temperature decrease greatly, and its extrapolation value of 105 h endurance strength is 36% lower than that of the standard recommended value. The residual life of low hardness straight tube section of high-pressure steam pipe is 54 075 h, which means the operation of the power plant unit has great security risks.

Key words: P91 steel tube, long service, low hardness, high temperature rupture strength, M23C6 phase

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